Arguing is human nature. In sports, more-so.
I don't see anything unique about this. In this case if a position isn't solidified, there's a legit argument to be made. As far as Dalton vs Fields is concerned, the overall issue argument actually seems to be is Fields ready or not. If not, that's where Dalton comes in.
Look at some of the fans around here. Neanderthal, leather helmet football fans who still have dirt in their nails from the 1960s. They're still living in a different era of football "logic". Mitch is a passenger on a 12 win team and he's labeled "winner" despite giving the Bears average QB play, with 1 game vs a dogshit team making up 25% of his TD production. Rodgers labeled "choker". This isn't accurate. This is Bears fandom speaking.
Some people post with their brains. Others with their hearts. I remember Packer fans arguing in 2013 about Rodgers vs Favre. This will be a thing forever.