I have been wavering in my "Fire Arians" position, but I think I still want him to go for this reason:

He asks guys to do things they can't do,

Like Spaeth to block.   Spaeth will not have a job in the NFL if we cut him today.

Our o line is not great, yet he telegraphs runs and passes- like shot gun on third and 3, or third and goal from the 3.

 He empties the backfield when we are not a great pass blocking team.

He telegraphs runs into 8 men in the box.

 He runs 3TE formation that rarely works. He will call a pass play out of 3TE set, when Spaeth and Johnson cannot get open.
He does not call play action enough, although it works beaufully, and almost perfectly. 

 He calls a sweep on 3rd and 4 with our slowest back.

Our QB is getting killed, but the screen pass and draw play are rarely called.

He almost refuses to max protect, even when our line is getting killed.

He calls 5 wide (instead of leaving the  RB in the backfield) even though we have never completed a pass to the RB when split wide.

He does not adjust to games, weather conditions, or performance of the team.  We won last year because of Defense, and Ben.  Without Ben, Arians would be nothing.  I doubt he will be fired, but I think we can do better.