To continue:
90.9 - Final score 21-18, opponent Steelers scored 24.3ppg in the regular season, the Colts had 0 turnovers in the game, the Steelers turned the ball over twice in the game, Colts plays per drive were 3/3/5/3/15/6/3/6/6/4/5. Not the defense's fault.
97.7 - Final score 28-24, opponent Chargers scored 25.8ppg in the regular season, Colts committed 3 turnovers (2 INTs) in the game., Manning was picked off at the SD11 and in the SD endzone, costing his team a likely 10 points minimum. This one's a much closer call then the previous losses, and the defense gave up 4 drives of 74+ yards for TDs, but Manning pissed away 10 easy points in a 4 point loss, against a high scoring opponent. In the end, you can't blame the defense for that loss, although you can certainly call it out for a share of it.
90.4 - Final score 23-17, opponent Chargers scored 27.4ppg in the regular season, Chargers committed the game's only 2 turnovers, 3 of the 4 Chargers' scoring drives started in Colts' territory, Manning threw for 310, but the Colts running game generated only 64 yards on 22 carries. You can't blame the Colts defense for that, either.
88.5 - Final score 31-17, opponent Saints scored 31.9ppg in the regular season, Peyton throws for 333 yards, but only goes 1/1 TD/INT and the INT is the only turnover of the game (at the Saints 26) and ended any chance of a comeback. This is the onsides kick game, and the Colts had the lead going into thee 4th quarter, but Peyton couldn't get it done (Drive stalled, and FG missed, at the NO 33, drive ends in pick at the NO26, Drive ends on downs at the NO5). The defense certainly didn't do a lot to help, but Peyton came up empty on three 4th quarter drives that got inside the NO 35, and the onsides kick recovery was a key to that game. You can't blame that on the Colts defense.
108.7 - Final score 17-16, opponent Jets scored 22.9ppg in the regular season, this is the Sanchez game after the Jets took down the Patriots (2010). The only turnover of the game was lost by the Jets, Manning went 18 for 26, but only got 225 yards out of that and, on their last 3 drives of the game, the Colts had to settle from FGs that were from the Jets 29, 14 and 32, because the offense couldn't finish the drives. You can't blame that on the Colts defense.
88.3 - Final score 38-35 (Manning now a Bronco), opponent Ravens scored 24.9ppg in the regular season, the game ended on a FG in overtime that was set up by a Manning pick in Broncos territory. This is the game where Flacco did the wing and a prayer throw to Jacoby Jones that tied the game at the end of regulation. Manning also threw a pick-6 in this game. This is a game where the defense definitely contributed to the loss, but Peyton directly gifted 7 points, and indirectly gifted the game winning 3 points to the Ravens, as well.
73.5 - Seattle SB, blown shotgun snap and the game was already over. Peyton wet himself when the pressure was on. That's not on the defense.
75.5 - Final score 24-13, opponent Colts scored 28.6ppg in the regular season, Peyton had 46 attempts for just 211 yards and had a fumble which led to a Colts TD. Broncos defense forced 2 INTs of Luck, but Peyton & Co. still managed only 13 points. That's not on the defense.
And, remember, in the 2006 run, Manning's best QB rating was 81.8, yet the team managed to win 4 and get the SB, because he rode the his defense to the title. Even in his 2015 run, his QB ratings were 74.4/90.1/56.6, and he had only 2 passing TDs (and 1 INT) in the 3 games, while his defense force 7 turnovers in that same stretch.
I think that says pretty much all there is to say about the "Manning's defense let him down!" angle.