You're moving from a verbose, bloated, over-engineered system to a terse and simple system. I think you're looking for something that doesn't exist because it's not how Ruby programmers work -- they use a language small enough to actually keep in your head and that's a huge part of the productivity to be had.
My ride with RoR hasn't been smooth so far. Far from having my first web app running within minutes. Instant Rails didn't work at all, and I spent hours trying to find a database driver for MySQL for Ruby. It's all very confusing. I suspect there is already a database driver bundled with RoR, but how would I know (documentation, where are you)? Googling only led me to some strange page where you could compile your own driver from C source code (and with what compiler, if I am on windows), which presumably was in some kind of alpha stage.
At least with Java I know that there usually exists a stable and proven solution... The training wheel analogy was maybe not so bad at all: Java applications just tend to be more stable than the scripting stuff. And other than bikes with training wheels in the real life, Java is also faster.
Also whenever I take on a new programming contract, I just start the computer the company provides me with, download the Java documentation and off we go.
Fad paradigms: no, but I know that if I need something, someone has already written a framework for it.