I know there were a few people who preferred the idea of certain shared skills between classes, but there very definitely was never a way for one class to get "any" skill. TL2's design was meant to get away from that, partly by the removal of those kinds of "pure stat increase" skills, and partly by making each class more unique and distinct from the rest. It's worth mentioning the ones that were shared weren't actual usable abilities they were the boring passive skills, like +% to block, or +% to crit, or decreasing vendor prices. the two systems aren't all that different, with the exception that a few skills (not that many) in TL1 were shared between classes.
I feel like you might be mischaracterizing the Torchlight 1 skill system.