Firstly, I choose not to play in 1 or 2 day limit games because I cannot guarantee that I can make it onto here every two days (I usually do but the day will come ... :) and if I enter a game or tournament with a longer time frame so be it, I have accepted it. If some wish to play quicker then they may set up their games and/or tounaments that way.
Secondly, I guess the x moves/y days option would have separate time clocks for each party so that if you were losing you could not wait until there was perhaps 5 seconds to go then make your next move (doesn't matter how many moves you have to go) and, voila, your opponent times out, a win from a lose. So the 10/30 could still take 60 days for the first 10 pairs of moves just like say a 3 days/move game.