I disagree with your premise that only a small minority of fans that regard Prescott as an average QB. Perhaps I should qualify my statement in that he's regarded in the 11-20 bracket of QBs in the league by those fans. I suppose a "good" QB would be ranked 11-15 and an "average" QB would be ranked 16-20. He's somewhere between the two along with the likes of Jimmy G, Cousins and Carr. All of whom are solid game managing quarterbacks like Prescott.
People take such offense to those comparisons...that's Jimmy G who has a 21-5 W/L record with a QBR of 100.0, 67.5% passing completion and has reached a Superbowl as a starting QB, Cousins who had 56 TDs and 16 INTs with an average QBR of 104 over the past two seasons and Derek Carr a 3 x pro bowler with 143 TDs and 62 INTs in his career. It's so offensive to be put in the same bracket as those guys! Jesus wept.
Prescott isn't Rodgers, Lamar, Brees, Wilson, Mahomes, Brady etc and there's no shame in admitting the same.
All Cowboy fans matter and it's an insult to state otherwise. Whilst I completely disagree with some fans, I do not belittle them by claiming that they do not matter.