Dude, he does have some factual basis for it, the most important part being he's an NFL scout.

A person's opinion does not mutate into fact because of their occupation. All it does is lend more validity to their opinion.

The Pats scheme has done this with multiple receivers of the same caliber.

Really they've done it with two guys, Wes Welker and Julian Edelman. I don't think that's really proof that they can do it with any guy. Troy Brown doesn't really fall into the same category as Welker and Edelman. The scheme didn't make Brown into a 100+ catch receiver. Troy Brown turned Troy Brown into a 100+ catch receiver by being one of the hardest working guys in football.

Not every team has an all time great, GM/Coach, and QB (Owner too?).

No, but every team in the league has eyes and ears and a brain and can figure out for themselves that if one team can bring a guy off the streets and make him a 100 catch receiver, they can probably do something similar. Seriously, if other teams looked at Wes Welker's production and thought he was a talentless hack, do you think they would say "Oh, well, the Patriots are just really smart and we could never hope to do anything like that," or do you think they would say, "Wow, we should try something like this." And do you really think Bill Belichick is that much fucking smarter than everyone else in the league that if they thought the latter of those two, they would be unable to duplicate any of the success that he had with Welker?

I'm fine with the statement that Wes Welker is overrated. What I don't like is hyperbole, and that's what this opinion screams. There aren't 100 slot receivers better than Wes Welker. He's not a terrible football player who was turned into a Pro Bowler by a smart coach with a great QB and an effective scheme.