Give Dan Orlovsky that Seattle team last year and Danny-O would be sporting a super bowl ring.
But the whole argument over making certain receivers better is way more complex then at first glance. WRs that come out of nowhere and do well, then leave that place and do poorly can be accounted for many things besides the QB. Look at Eric Decker for instance. Young WR, that made out as the least payed attention to weapon on that Denver offense. He wasn't anyone before that, but then again hadn't ever had a chance to be anyone before that either. But, he leaves a pass offense, hall of fame QB, great all around supporting cast, and great coaching staff to go to the Jet's...
So did Peyton Manning make Decker great? Idk... Is Decker just bad since this year he is subpar in New York? By all accounts people believe that Larry Fitzgerald is a bonafide great WR. Even though without missing games the last two years his stats are Golden Tate esque from last year. And crappy Eric Decker will probably have numbers similar to those years by Larry Fitzgerald.
Fact, is QBs can make some WRs better, but not by some huge margin. Bad WRs won't make a team let alone start or have meaningful playing time. Can a great QB improve a WRs stats by say an extra 200yds and 4 TDs over a year? Of course. But, you don't normally see a scrub like for instance Jeremy Ross all of a sudden become Steve Smith Sr just because of a QB.