You want an official to time each match with a stopwatch?
As for completely abolishing the time limit.... it's just a bad idea. The point of it is to stop matches from lasting forever. Most matches wouldn't, but then you get extreme cases like Armada vs Hbox, where they both had two stocks left at the end of a game. And no, it's not because they both tried to time each other out, but rather a direct result of Armada's YL camping matching up with Hbox playing patiently in order to avoid getting with projectiles.
In most cases though, I believe the timer acts as a deterrent from building a strategy solely on keep-away game, at least until a certain point. It sounds ironic, but my thesis is that the existence of the timer tells the players that they have a deadline, and they need to get the match done before that. As said, until a certain point, where this psyochological effect wears off because the time limit transforms from a deadline into a goal line.
I don't know if anyone else experiences the time limit in this fashion, but if you do, you can see why it shouldn't necessarily be shortened.