No, it is not. Most JVM languages (except Ceylon, I think) choose to erase generics, as that's the right thing to do if you want good polyglot interop.
No, I mean that the JVM itself doesn’t have opcodes for storing generics type info. Hence why it was done for backward compatability, they didn’t need to add or change instructions.
That's incorrect. You could specialize classes on the fly (and the opcodes for all reference types are the same, anyway). It's just that it's a bad idea to reify generics of reference (and so subtypable) types. You gain little and lose much.
