You're implying Flacco doesn't win regular season games when he has made the playoffs every year of his career and has a 67.5 career winning percentage which if maintained would put him above people like Brett Favre, Jim Kelly, Dan Marino. Maybe we need a definition of better? You mean strictly from Y/A better, or do you mean NFL better.
The quarterback is the most important player on the team, but ultimately he's just one piece of the puzzle. Part of the reason why guys like Rodgers, Eli, and Flacco have won Super Bowls in recent years is because of the players around them. That's not to say that those guys aren't good QBs. They are. However, it's important to point out that they're also
good QBs on good teams. So when you start using things like wins to argue one QB over another, I think it's a bit misguided. The supporting cast is a huge factor. In Flacco's case, the fact that he plays on a Ravens team that always drafts well and always has a really tough defense goes a long way towards explaining why he has appeared in the playoffs so frequently. It's not like he's been carrying bad teams on his back. I would be saying the same things today about Kaepernick if his team had won. He made some great plays throughout the postseason. On the other hand, he's not the entire team. Frank Gore, Vernon Davis, Michael Crabtree, Patrick Willis, Justin Smith, Aldon Smith, Navorro Bowman, Donte Whitner, and others are a big part of the reason why San Francisco has been a tough team in recent seasons. Stick Kaepernick on the Ken Dorsey 9ers with Brandon Lloyd and Cedric Wilson as his top two receivers and an inept coaching staff and front office calling the shots, and he probably doesn't even make the playoffs this year.
I'm pretty consistent when it comes to how I evaluate QBs. Whether the topic is Ryan, Roethlisberger, Wilson, Newton, Flacco, or Stafford, I typically point to the same stats. I look at completion percentage, YPA, TD:INT ratio, and QB rating (which is basically just a measure of those other stats). These are the things that I've emphasized for years. If a player is weak in these categories, it's pretty unlikely that I'll consider him a great NFL QB. You can call that stubborness, but it's completely transparent and consistent. It has very little to do with bias against specific players. It's just a reflection of which stats I happen to value. And the players that I value will be an extension of that.
Flacco played great in the postseason. In that regard, he proved me wrong. I never thought he would be a big game QB. However, in terms of his overall performance, he's not really in the discussion as an elite pro at the moment. If you want to compare him to other NFL QBs, the way I would approach that question would be to ask myself who I would want if I had to win a game tomorrow with a generic supporting cast. I'd definitely take Peyton, Brees, Rodgers, and Brady over Flacco. I'd probably take a healthy Roethlisberger over him. I think he's a coin flip with Stafford, Eli, and Ryan. I think Kaepernick, Wilson, Luck, Newton, and a 100% healthy RGIII would give you a similar chance to win right now. I foresee a couple of those guys clearly surpassing Flacco in the next year or two. So he probably checks in somewhere around QB8-QB12 in my rankings of current NFL QBs. Solid, but definitely a notch below the elite. And until he sustains elite performance over a complete season, there's little reason to adjust that thinking.
Overall, I don't think you're looking at this from the right perspective. The question isn't "Can Joe Flacco win games with the Ravens?" We know the answer is yes. The question you should be asking is, "Could Matt Stafford win games with the Ravens?" And "Could Cam Newton win games with the Ravens?" And "Could Aaron Rodgers win games with the Ravens?" And so on. Because when you rank a player in terms of his real life NFL ability, you're supposed to separate him from the context and ask yourself how he compares to his peers on a level playing field. And when you look at things from that standpoint, you'll start to see why I have Flacco as a top 8-15 guy and not a top 5 guy. He's solid, but lots of QBs would win in the same situation.