For English I assume it means a global language. For why English has become a global language, I think it's more of a question about history, instead of PLDI. Here I answer why a programming language would choose keywords from a global language.
Firstly, as Seggan commented, there are a lot of programming languages using other natural languages. But it is much less likely someone would get to know a programming language not in either English or their first language. If you use English, you have a much broader user base, that could potentially get your language much more popular. If someone wants a broader user base, they would also choose English. So, in the end, the most popular programming languages you have known are in English.
I think there are only two alternatives for this purpose. One is to make it multilingual.
There were some animation makers and game designers that had a way to make easy programs using a GUI list of commands, and the commands tend to be translated. It's easy because the translation doesn't change how the code is stored, but only how they are displayed. But users switch to the traditional way quickly, because the graphical way usually only support a restricted set of features, and the editor isn't very easy to use. Better examples on this direction would be Scratch-like languages. I don't know Scratch much, but I think it's much more powerful than the GUI lists, but still not as powerful as modern advanced languages.
The obvious problem of supporting multiple languages in traditional text programs, is the identifier names could easily conflict with keywords or system libraries in a language that the programmer doesn't know, or not even existed before the program has created. It might be better if the programmer chooses the language. But there is another problem, that translations tends to be slower than the original release, and if it's not the original developer making all the decisions, sometimes translations are bad and are subject to change, which would be very undesirable to use in a programming language. The programmers could use English before the translations are stable, but they would still have to learn the English version, adding more difficulty to just use English, and they would need an automatic translator to change the language afterwards. A potentially better way would be like the GUI lists, that only translate the words in the editor. In either case, I think they are not considered reliable operations for program source code, especially with eval and homonyms in consideration.
But I don't think these difficulties are absolutely unsolvable. Maybe someone could come up with some clever ideas. And they could start from languages that least likely conflict with English. I think the real problem is, keywords are not the only thing in a programming language. Documentation and libraries matter more. A translated programming language is of no use, if there are not documentations at all. And not many language designers had the resources to maintain documentations in that many languages. Library writers usually had less resources. That also answers why there had to be a popular programming language, instead of everyone using their own programming language in their own country: Actually there is not much reason for a programming language. You could do it if you had enough funds. But the reason is strong for libraries, and languages don't affect that much without libraries. A possible middle ground is, make everyone use their own language internally in a project, and export the symbols in English, to make a library popular, cost-effective, and non-English. But it might be difficult for us to know it is the case.
TL; DR: The majority of libraries would support only one language, and you'll not know it if it is not English. Programming languages doesn't contribute much to the whole picture, but have extra difficulties, that may not worth it.
Another way is to use symbols, like APL. But that only applies for a small set of builtins. They still have to use words in natural languages if there are a lot of libraries.
Also note that while programming languages borrow words from natural languages, they are not the same. Some words like "for" "yield" are too generic but have gained much more specific meaning. But they may not affect translation.
Survey about the documentation languages in some programming language's homepage
Python has English, Spanish, French, Japanese, Korean, Brazilian Portuguese, Turkish, Simplified Chinese, Traditional Chinese, 8 or 9 languages
PHP has English, Brazilian Portuguese, Chinese (Simplified), French, German, Japanese, Russian, Spanish, Turkish, 9 languages
Rust has English (en-US), Espa?ol (es), Fran?ais (fr), Italiano (it), 日本語 (ja), Português (pt-BR), Русский (ru), Türk?e (tr), 简体中文 (zh-CN), 正體中文 (zh-TW), 9 or 10 languages
Ruby has Български, Deutsch, English, Espa?ol, Fran?ais, Bahasa Indonesia, Italiano, 日本語, ???, polski, Português, Русский, Türk?e, Ti?ng Vi?t, 简体中文, 繁體中文, 15 or 16 languages
C# has Bahasa Indonesia, Bahasa Melayu, Bosanski, Català, ?e?tina, Dansk, Deutsch (?sterreich), Deutsch (Schweiz), Deutsch, Eesti, English (Australia), English (Canada), English (India), English (Ireland), English (Malaysia), English (New Zealand), English (Singapore), English (South Africa), English (United Kingdom), English (United States), Espa?ol (México), Espa?ol, Euskara, Filipino, Fran?ais (Belgique), Fran?ais (Canada), Fran?ais (Suisse), Fran?ais, Gaeilge, Galego, ???????, Hrvatski, íslenska, Italiano (Svizzera), Italiano, Latvie?u, L?tzebuergesch, Lietuvi?, Magyar, Malti, Nederlands (Belgi?), Nederlands, Norsk Bokm?l, Polski, Português (Brasil), Português (Portugal), Roman?, Sloven?ina, Slovenski, Srbija - Srpski, Suomi, Svenska, Tiê?ngViê?t, Türk?e, Ελληνικ?, Български, ?аза? т?л?, Русский, Српски, Укра?нська, ??????,? ???????, ?????, ???, ???, 中文 (简体), 中文 (繁體), 中文 (繁體 香港特別行政區), 日本語, 48 or 69 languages
Scratch (user languages) has А?сш?а, Afrikaans, ???????, ????, Aragonés, Asturianu, Azeri, Bahasa Indonesia, ?????, Беларуская, Български, Català, ?esky, Cymraeg, Dansk, Deutsch, Eesti, Ελληνικ?, English, Espa?ol (Espa?a), Espa?ol Latinoamericano, Esperanto, Euskara, ?????, Filipino, Fran?ais, Frysk, Gaeilge, Gàidhlig, Galego, ???, Hausa, ???????, ????????, ?????, Hrvatski, isiXhosa, isiZulu, íslenska, Italiano, ??????? ???, ?аза?ша, Kichwa, Kiswahili, Kreyòl ayisyen, Kurd?, ?????? ???????, Latvie?u, Lietuvi?, Magyar, Māori, Монгол хэл, Nederlands, 日本語, にほんご, Norsk Bokm?l, Norsk Nynorsk, Occitan, ?????, O?zbekcha, ???, ?????????, Polski, Português, Português Brasileiro, Rapa Nui, Roman?, Русский, Sepedi, Setswana, Sloven?ina, Sloven??ina, Српски, Suomi, Svenska, Ti?ng Vi?t, Türk?e, Укра?нська, 简体中文, 繁體中文, 76 or 80 languages