My understanding is that us non-tonal language speakers butcher their names anyway, both in pronunciation and in remembering them. I've asked multiple Chinese acquaintances of mine what their Chinese name is and I struggle to pronounce their names properly even with some coaching, and I very rarely remember them afterwards. And I'm pretty good at languages in general.

These names exist in a linguistic spectrum that is different than Indo-European languages, which our brains are tuned for. It's just a lot more practical for Chinese people to get a Western name.

It's less necessary, because there are more Chinese computer systems that correctly support ascii names than English computer systems that correctly support GB/Big5/UTF16