I love the fact that I can be "doing something" while not in Glitchland, because it keeps my interest high for playing when I'm... say, at work, but there should be a penalty for offline learning (or, if you will, a bonus for learning in-game).
As Artilect said, the benefit to being online is that you can accelerate the learning process.
I actually like this feature because it allows casual players to progress reasonably quickly through the skill trees instead of being held back by a lack of time to play.
agreed, I tend to speed up skills to maximum while in game so that I can enjoy and use the new skill when I come back to the game (due to work, sleep or, dog forbid, actually leaving the house =) ).
While I see the point of the comments about offline learning, I think learning should only be done while in the game. I could keep logging in, starting a skill, then logging out again. Which is kind of silly. Learn while you play. If the devs need to adjust learn times accordingly, than so be it, but offline learning seems odd. My 2ยข anyway.
I agree with the responders; I love this aspect of the game and actually think that the other aspect of "better-than-thou-through-grinding" design -- levels -- would ideally be eliminated, as well. Glitch is a small game, but it stands tall in its lack of emphasis on self-improvement. You have to learn skills, so in that one way, pros can do some things noobs cannot, but in general, if you have friends, all can be achieved easily and sensibly. You cannot buy or OCD your way to "success". I love this about Glitch. It reduces my tendency to obsess over perceived progress.