What made me switch to Ruby was after I as an experiment rewrote a queuing middleware server that was about 5k lines in C, into about 500 lines of Ruby that had more functionality. It was slower, sure, but it drove CPU load from 1% to 10% of a single core before we hit disk IO limits, so it just didn't matter. What did matter was the improved maintainability of simplifying the codebase that much..

The point being that often the "hulking layered codebase" doesn't need to be.