So having an elite QB would make Holmes desirable...sort of like when he had Roethlisburger throwing to him and he went for a fifth? Fail. You also just said he was basically on the level of Woodhead, who is also on the level of Welker.
See, stats aren't what smart talent evaluaters use, which is why people who think a player is "better" because they have a good QB are inherently wrong most of the time. Holmes would produce more with Brady, but he would be the same lazy player who is a few balls-thrown-in-the-other-direction away from quitting on his team.
Good players are like Welker. When Welker went to the Patriots his production jumped from 700 yards to 1100 and his TDs from one to eight. Did Brady "make" him 80% better of a player by existing in the same stadium? No. Welker was basically the same player he was. Has Welker's production gone up after six seasons with Brady? No. Welker is, largely, the same caliber player he was leaving the Dolphins.
Certainly he has developed his skills, but this goofy idea players are better because of their QB is actually not goofy, it is wrong. Players produce better with a better QB because, duh, the talent around them is better. Thinking that a good team would be interested in Holmes is silly...anyone would be better in the sense you are talking about with Brady or Manning than with Sanchez or all but two or three other QBs in the league. Which is why teams like the Patriots and Broncos and Packers don't have to sell out for a scrub like Holmes. NY took a risk on a cut-rate car no one else wanted and got burned because it was a lazy PoS that only worked when it wanted to while the teams who have good QBs.
This isn't a vacuum. Good QBs make their teams look better, bad QBs make their teams look worse. Good QBs are improved by building around them, supporting them, and looking to the future. Bad teams ruin every chance they get by pursuing easy dollars and headlines or trying to bring in the discounted player-of-the-week. Good teams don't do what you're doing, thinking a player finally lived up to their potential under the hypothetical that they have the best QB in the league throwing to them (and justifying their poor production because of how bad their old QB was) they look at the work they actually do and judge them on that.