On Wednesday night, the 98-win Pittsburgh Pirates were eliminated from playoff contention after one game. They had the most wins of any team to not make the Divisional Series since the wild cards inception in 1994.
We live in a very reactionary culture today. Some college football player threw for 500 yards and 5 touchdowns in week 1? He's the next Johnny Manziel. Colin Kaepernick has one dominant playoff game, and suddenly Ron Jaworski is hyping him as the "greatest QB of all-time." Spend five minutes on Twitter and all you'll see are quick reactionary opinions. So in other words, don't spend five minutes on Twitter.
The newest issue seems to be that the MLB playoff structure needs to be tweaked again. A one-game series isn't fair! Right? Technically, it's not fair. But the playoffs in general are not fair. Teams play 162 games over six months, but then the champion is determined by a maximum of 20 games (max series lengths are 1-5-7-7) over three weeks in October. If people truly want the "fairest" result, the regular season's best record should be the champion, much like Soccer.
Most people would hate that idea, myself included. The playoffs have become a major part of our culture, and the considerably shorter playoff stretch fits into our reactionary culture much better than the 162-game regular season would. For entertainment purposes, the playoffs are a must. And let's be clear: despite pro sports being a multi billion dollar industy, the point of sports is for entertainment, no matter how many people forget that.
The current (and fairly new) set up was designed to give incentives to teams that win their divisions. The goal was to make winning your division more important than it had been since the introduction of the wild cards in the 1990's. Why? Because baseball loves it's traditions. And for 100 years before the introduction of the wild card, winning your division was a must to make the playoffs. So the current setup is a compromise between making the playoffs more fair (5 teams from each league now make it) and entertaining (4 of those 10 teams play in a 1-game playoff).
Ratings also play a major part in the decision to make the game an elimination game. The always great Wikipedia (your high school teachers are wrong) allows us to look at the television ratings for each world series game, dating back to 1984. The World Series will almost always draw more viewers than a Divisional Series game, but the premise is the same: fans tune in more when the series is about to end. Game 1 has great ratings, because we love beginnings, but game 7's have way better ratings. Elimination games in general get better ratings. Game 4 of the 2012 World Series between the San Francisco Giants and Detroit Tigers, with the Giants leading 3 games to 0, drew 3 million more viewers than any other game, and 5 million more viewers than game 3.
So Major League Baseball used game 1 as the elimination game. And it's worked great. This year's Yankees-Astros game on ESPN was the most viewed MLB game on their network in 12 years, and the most viewed wild card game in the new system. That's mostly because the Yankees always draw better ratings than other teams (even if some people just tune in to root against them), but at least some of it has to be the lure of a great season ending in one night. It's certainly unfair, but since we really just want entertainment, the current system fits the American public's preferences very well. Leave the damn thing alone.