Well I think it has to do with the vast amount of 'stuff' in the ASL rulebook. For me, trying to remember which rule/diceroll is applicable when is the issue. I guess I think 'just let the computer handle that'; which may or may not be realistic.
Also, it seems whenever someone posts a picture of one of the various ASL tourney's, the folks in the picture are inevitably referring to the ASL rulebook rather than enjoying the game.
However, it just may be that part of the joy that comes from ASL is finding that rule that:
1. renders you opponents brilliant move illegal.
2. makes your questionable move/strategy legal.
3. shows your superiority in remembering obsure rules rather than any 'tactical'/game playing acumen you actually have.