Literally no one, anywhere, wants to be forced to read source written in a language they can't read (or more specifically in this case: written in glyphs they can't even produce on their keyboard). That idea, for almost everyone, seems "horrific", yeah.
So a lingua franca is a firm requirement for modern software development outside of extremely specific environments (FSB malware authors probably don't care about anyone else reading their cyrillic variable names, etc...). Must it be ASCII-encoded English? No. But that's what the market has picked and most people seem happy enough with it.
This is blatantly false. I'd posit that a solid 90% of all source code written is done so by single, co-located teams (a substantial portion of which are teams of 1). That certainly fits the bill for most companies I've worked at.