In the real world, [Tom] Brady's playoff career is pretty similar to Derek Jeter's, a guy who repeatedly won at the beginning of his career before a long stretch of mostly coming up just short. Flip it, and he's more like [Michael] Jordan, a guy who had the playoff choker label slapped on him before making the whole thing look silly. Winning in the playoffs matters, but a win in the 10th year of a guy's career means just as much as one in his second year.
Once you get past the idea that there's something specifically troublesome about Ryan losing his first three playoff games as opposed to three randomly consecutive playoff games, it looks a lot less meaningful in terms of defining his skills. In addition to Peyton Manning, plenty of legendary NFL quarterbacks have lost three consecutive playoff games during their careers. Marino. Elway. Brady. Aikman. Even Joe Montana did it: After he won the Super Bowl in 1984, Montana lost each opening playoff game in 1985, 1986, and 1987, only to promptly go 6-0 and win consecutive Super Bowls immediately thereafter. Did Montana forget how to win in the playoffs and suddenly remember? Of course not.
There's no guarantees that Ryan will experience a turnaround in his playoff performance similar to that of Montana or Michael Jordan, of course, but there's also no evidence that his three playoff losses say very much about his likelihood of winning playoff games in the future.
If your argument against Atlanta's playoff chances revolves around the idea that the Falcons are limited without a healthy Julio Jones and haven't delivered many big wins during the regular season this year, you have a fair point. If you truly believe that the Falcons aren't a legitimate contender because they haven't won a playoff game with their current core, though, you're convincing yourself that three losses against very good teams means more than Ryan's excellent body of work over 74 regular-season games. History tells us that's foolish. There's no reason to wait until an Atlanta playoff win to believe that they can compete in this year's playoffs. It has long been time to take Matt Ryan and the Falcons seriously.