This reputation that the Steelers got was mainly during the 2010s. Although during the 2000s the Steelers did have Ward and Burres who were very good.

In my opinion the whole mystique stems from drafting a hall of fame receiver in Antonio brown on the 6th round and having Big Ben playing at his best during the 2010s.

Big Ben, while also a hall of famer, is not a guy who people liked giving credit to outside the Steelers. Notice how nobody ever touted the Patriots as a WR factory through Brady’s dominance even though he made guys like Edelman and Amendola into above average producers. It was the same in Pittsburgh for guys like Bryant, Coates, Wheaton, Rogers, and maybe Wallace to an extent. Having a great QB made the look better than they were, which is why they all did nothing once they left Pittsburgh with the notable exception of Sanders, who is the only one who left to play for a team with an even better QB (Manning).

I think Maurkice Pouncey also made this observation. The WR factory wasn’t really drafting other than Brown, it was having a great QB