Skwatcher:
It's rather the fact that most programming language today is in English, and since the PLA wants to use civilian expertise in programming, it's simply more practical to let these programmers continue using English commands. I guess the programming would be twice as complex if each command would have to be written and then translated into Chinese before appearing on the display. Could be an export version though, as speculator....speculates
I think I remember reading somewhere that the PLAF used C++ as the programming language for the J-10 suite. My memory might serve me wrong though.