The basic idea that you're expressing isn't entirely unreasonable--not everyone should spend the time to become a competent auto mechanic just because. And it's not unreasonable to just take your car in to get the oil changed. However, you're probably getting downvoted because:

1. AAA isn't always there at your beck and call. 2. The mechanics of changing a flat don't exactly take years of training. 3. Some degree of self-reliance is generally desirable although that degree may be a reasonable topic for debate.