Sure, it's a team game and there is some FO blame in there, but every team has flaws and areas that don't get addressed as well as fans think they should. The fact remains that in both of the cases I cited, the team as constructed, including #12, was good enough to win the NFC Championship. Had the on-field performance on game day been just a bit better, especially against Seattle, you would have been in a Super Bowl.
It doesn't matter at that point if #12 masked flaws or not. The loss to the 49ers revealed a clear personnel deficiency but the other 2 recent losses were not due being overwhelmed from a talent perspective but rather due to mental errors by individual players on the field, including #12. The players and coaches bear the majority of blame in both cases.