[dmoy]

> don't understand why Chinese speakers don't put more [any] emphasis on using names that they are themselves able to pronounce, like Tina or Julie.

Some are assigned an English name by their first English teacher in school. This English teacher themselves may not really be able to speak English (e.g. this is the case for more than one person in my family). By the time they figure out otherwise, it's kinda stuck/habit.