Many times, though, UML is generated after-the-fact (from code using Rational's software) and in absense of actual design, planning, and API/design documentation.

Definately agree here. Such "reverse engineering" of code into a UML diagram is really anti-design. If such tools are used at all, they should only be on old projects that were created without the benifit of a UML (or similar) diagram. If your project has a requirement to generate UML, do it before actual code is written.

See how many pages of the J2SDK documentations you have to read to fully understand a particular method call.

I don't miss the days of having to intilize at least two objects just to read a file line-by-line :)

Java, in fact, was something I liked.

Same here. I was enticed by its clean (though impure) object system. But that blasted API got to me after a while.