The way this thread reads, we should just eliminate playoffs in all sports. Let's just subjectively crown a champion at the end of the regular season. I am amazed by the harping on baseball playoffs, considering with the exception of college football, every sport at every level has playoffs.
Personally I like the playoffs mostly as-is, though I'd certainly make a few changes... i.e. fewer off-days and a 7-game series in the LDS instead of 5. That said, while I like interleague play, I would not be opposed to going to a 168-game schedule of playing 12 games round-robin within your league doing away with divisions, and then having a 9-game World Series among the two league champions.
Short of doing that, however, I don't think the problem is necessarily with having 5 teams from each league making the playoffs, but rather how the playoffs are set up to begin with. The whole season is a marathon and they've got the playoff schedules set up to be a sprint. The wildcard round adds an extra team but it also restores the importance of winning the division -- at least in theory. In practice, it would restore the importance by going to a 7-game LDS; cutting out the extraneous travel days during a series; and lastly, playing all the games in a series at home of the higher-seed.
"No matter how good you are, you're going to lose one-third of your games. No matter how bad you are you're going to win one-third of your games. It's the other third that makes the difference." ~Tommy Lasorda