Russell Wilson has played against the 22nd, 23rd, 26th, and 29th ranked passing defenses in the league. Is he not a legit downfield passing QB since he accumulated stats built off the backs of bad pass defenses?
Matthew Stafford has played against the 21st, 25th, 29th, and 30th ranked passing defenses in the league. Is he not a legit downfield passing QB since he accumulated stats built off the backs of bad pass defenses?
Patrick Mahomes has played against the 19th, 28th, 30th, and 32nd ranked passing defenses in the league. Is he not a legit downfield passing QB since he accumulated stats built off the backs of bad pass defenses?
Point is, every QB is going to have bigger days against mediocre/bad defenses and struggle more against good ones. I'm not saying Dak is as good a downfield thrower as Mahomes or Wilson, but you shouldn't throw out a blanket accusation when reality makes it illegitimate.