A few things to consider:
First, yes 19-0 is a bit overkill but how much worse is it than 10-0? Slaughtered is slaughtered, and as far as a slaughter rule if a team is truly weak, then taking them off the field early in a lot of their games does not really help in their development as a team at all.
Second, if a team has all their reserves in the game who work just as hard at every practice as the starters then why should they be denied their chance to put a few in the back of the net. Personally, I would be more embarrassed by a team of reserves working the ball down to the goal line and then turning around because they are not allowed to shoot than a score of 19-0. Finally, I've lost games by up to twelve before, and to be fair, it's really not all that bad. When a team is far superior to yours, thats just how things happen.