There are really only two possibilities here.
1) Fox is trying to get fired and this is his way of flipping off Jerry Richardson
2) Fox is so thoroughly wrapped up in his love for veteran starting QBs that he'll even take a guy who's played so few games that he's still practice squad eligible at age 31 over a rookie.
Neither of those is a good thing. It's arguable which is worse.
The third possibility is he is trying to do the best he knows how with the crap hand he was dealt. He didn't make the decisions and had to choose between a crappy rookie who has had no reps and a crappy veteran who has at least played 5 preseasons so while he has only thrown 5 passes in the regular season, he has infinitely more experience than Pike or edwards who have little to none.
Not trying to excuse him but seriously I guarantee if he had his way, we would have tons more veterans on this team and we wouldn't be this crappy.