It's still not that hard. Plus, in many MANY languages outside of english, you can easily write in ascii.
German, Norwegian, French, Italian and Spanish all have a few extra letters and/or apostrophes or whatever. Nevertheless it's simple to use norwegian (or german, or italian) names for variables, functions and components.
Even if you -do- decide to use english names, that's STILL not equivalent to needing to know the language. You don't need hearing-comprehension (harder than reading-comprehension for many) you don't need grammar. You don't need pronounciation. You don't need comma-rules, capitalization-rules etc etc etc.
Learning a few nouns and a few verbs isn't more than a small part of learning a language.
Knowing english is helpful. It's in no way required.