Here's some numbers that justify my frustration with baseball's postseason and being a fan of a team in the toughest division in all of sports, the AL East.
In the 15 postseasons that have commenced since the Wild Card was implemented in 1995, two Wild Card Teams in the AL will have won the World Series: the 2002 Anaheim Angels and the 2004 Boston Red Sox. Their records, respectively, were 99-63 and 98-64. The only AL Wild Card team to have a better record than these two clubs is the 2001 Oakland Athletics, who finished at an impressive 102-60. The only reason they didn't win their division is because the Mariners won a ridiculous 116 games, an AL record that tied the 1906 Cubs' mark. Should that be a reason to not get home field advantage?
The 2002 A's didn't win the World Series. They didn't win the American League Championship Series either. But the puzzling thing is that this team did not even win the American League Division Series. They lost to the Yankees, 3-2. The Yankees, by virtue of having won their Division at 95-67, had home-field advantage, which ultimately decided this series. Interestingly, the A's were able to take both Game 1 and Game 2 from the Yankees in NY. They allowed just two hits in Game 3 in Oakland, amassing six themselves. They somehow lost this game 1-0, and lost Game 4 after allowing 7 runs in innings 2-4. In the deciding Game 5 back in NY, the A's took a 2-0 lead into the bottom of the second inning, but fell victim perhaps more to the home field advantage the Yankees has wrested back from them and the momentum the Yankees had winning the last two games than anything else, and lost 5-3, allowing the Yankees to move on to the ALCS.
I detail this ALDS to show how difficult it is to overcome homefield advantage in a five-game series in baseball, since as impressive as the A's first two games were and the A's themselves were winning 102 games on the season, they got really shafted out of a win in Game 3 with a two-hitter, anyone can win one game (Game 4), and the advantage was squarely back with NY in Game 5 if you adhere to the momentum phenomenon (you should) and remember that NY just had to win one game at home then to move on. I don't think it plays out the same way at all if the A's had homefield advantage, as I am arguing should always go to the team with the best record unless it would result in two teams from the same Division playing in the LDS (as it is currently).
I could do this for the NL but "totally different league" etc. The also have just two WS winners out of 14 (the NL Wild Card Rockies this year have yet to be eliminated), to note that. But while many strides have been made to take the emphasis off of winning the division (lol at four seven-team divisions and four playoffs teams in the then–28-team majors before the wild card), the focus still clearly seems to be on prowess in your Division rather than prowess in your League. And with five-game series, there seems to be even more of an obstacle for Wild Card teams to overcome, since home-field in baseball is perhaps more relevant than in any other sport as it actually decides who bats last. Comparing to the NHL, NBA and NFL, which have no such tangible advantage aside from the crowd, which baseball still has, and additionally when considering the fields of play in all four sports you see that the foul territory in baseball, and fielding fly balls in a dome (or not), and judging ground balls widen the gap of any "home field advantage" compared to the other three.
By rule, no Wild Card team will ever have home field advantage in the LDS or LSC (the World Series is determined by who wins the All-Star Game or, before 2003, simply alternated between leagues). Now the Angels had a better record than the Red Sox did, and thus very fairly deserved home field no matter what, but if I look at the actual records of the LDS and LSC teams in the last 15 years, I will probably be able to find more than a few instances where a team with a worse record had home-field advantage over a team with a better record, and won because of it given the actual advantage being at home grants you in the MLB.