It has a very strange type system. Funny syntax. Lots of unexpected behavior. Also could be compiled relatively easily if it behaved better, there are a lot of funky edge cases. It's also bad as a general computing language - anything where you aren't just computing on a bunch of matrices.

Nowadays I'd say just use python -- it's not _quite_ as nice when it comes to computing on matrices, but it's _much_ nicer when it comes to everything else.