Probably the biggest reason why people don't bother to learn a Jap is:
1.) It isn't free to attend lessons for another language. (Yes I know there are things like the internet that help, but some people learn better from textbooks and teachers.)
2.) Some people just don't have the time to learn Jap, so it is better for them just to wait patiently for a translation.
3.) It is not easy learning a new language and some people just can't be bothered with it.
Don't get me wrong what you said is true but it is infinitely easier to read something in your native language than try to read somethin