My theory is that football is complicated and most casual fans don’t have any interest in actually understanding it, so they obsess over QBs as a shorthand for offense.
Doing what you say—fixing the OL, RB, WRs—and what you don’t say—fixing the scheme and playcalling—is boring and complicated. A casual fan has no interest whatsoever in the difference between Jesse Davis and Morgan Moses. Nor can they even decipher that difference.
But everyone can recognize the difference between a 300 yard passer vs. a guy struggling to find open men and getting sacked. The casual fan has no idea what’s causing the 300 yards passing vs. the guy running for his life and struggling to complete passes, but they’re like “hey, we need the 300 yard passing guy!” as if we’d also throw for 300 yards every game if we had him.
This will blow a lot of folks’ minds, but the Dolphins have been terrible on offense for 20 years not really because of our QBs. The common thread is bad OL play and bad WRs. We’ve actually had pretty decent QB play for the last decade-plus, from Pennington to now.