You don't have to solve all edge cases for a feature to be useful. At least not all the time.

I, am not too unhappy with the behaviour of C/C++/Java/... - That the block comment will end at the first occurence of " * / ".

If I accidentally close a comment too early (because there already was another block comment inside the code I want to comment), then...

* The syntax highlighting of my IDE will tell me.

* The compiler will tell me.

* I can take it as an opportunity to consider whether this file is too large - That problem should not have happened at all.