People forget that crashes are a debugging tool indicating an error. Silent errors can be much more dangerous. C and C++ in particular need to be careful not to overwrite random memory for example.

Yes the consequences for JS failures are less severe and so JS can get away with it, but a crash is a way to know your program isn't doing what you thought it was, properly.

It just so happens that JS is used in contexts where nobody really cares, and errors aren't a big deal, cheap and fast wins.