why does java suck?

I've noticed in the short time I've been reading this board that there's a lot of java bashing, so I was wondering why people actually think it is so bad. I'm no java fan, but I've used it for some stuff before and it didn't seem terrible to me. An argument used to be that it runs slow as a guro-fied loli, but they've improved a lot in that aspect.

Please give good reasons, rather than stuff like "it's for certified professional consultants" or whatever you guys say.

But, isn't a 3D engine a realtime task?

Only loosely. I didn't mean real-time as in real-time rendering, I meant real-time as in soft and hard guarantees.

When I was teaching myself data structures, I did it in java. Why? Because there were lots of good java books for it

This: http://www.amazon.com/gp/product/0201000237/
This: http://www.amazon.com/gp/product/0201000296/
This: http://www.amazon.com/gp/product/0262032937/
And this: http://www.amazon.com/gp/product/0201485419/

These are the books for data structures. Not one of them uses Java inside. Whatever your reason for using Java, it's bunk.

let me do my own memory management comment

Why aren't you using C/ObjC/C++ then? If you strip out the GC, what you're left with isn't Java, except in the most tenuous sense.

why doesn't somebody do a compiler for all of these languages like python to compile to java bytecode.

Because they have syntax and semantics. If you mean the same target for several compilers, there's Parrot or (zomg!) x86.