I've done a fair amount of programming in Ruby (two reasonably large Rails applications, spanning about two years of development time). When switching to Ruby from just about anything else that I program in from JavaScript to Python to Racket to ML, I get tripped up on exactly this issue because it doesn't match my expectations at all.

My gripe is that the simplest, cleanest construct in the language for defining named functional abstractions---"def"---doesn't support closing over variables, which other languages do, so I have to warp my thinking a bit to program in Ruby. The analogous program in the four languages I mentioned above (and Pyret, and more) works and creates a closure. Maybe I just don't think well in Ruby, because I end up feeling frustrated that Ruby seems to not like functions.

All that said, "in fundamental ways" is a little harsh. At least in this example, Ruby hasn't done anything to violate the integrity of static scoping the way, say, JavaScript's "with" does. I'll try to see if I can come up with a better example that's a clearer problem and less a personal dislike.