I think most would expect more from a franchise QB.
There's a limit even to what a very good QB can accomplish. I went back to 1970 and looked at teams with similar make ups to that of the Cowboys from 2011-13.
The specific parameters were
for the QB:
Top 10 in passer rating and touchdowns
for the defense:
Bottom 10 in pass rating
for running game:
Bottom 10 in rushing attempts
rush TD below league average (any running game with a top 10 QB should be
at least average in the red zone)
The first ranking is defensive pass rating, followed by rushing attempts and rushing TD, then the QB's rank in pass rating that season.
These are all top 10 QB.
1973 Phi def 25th, rush (att 24th, TD 20th) Gabriel 5th 5-8-1
1980 NO def 27th, rush (att 28th, TD 25th) A. Manning 8th 1-15
1982 SF def 22nd, rush (att 27th, TD 17th) Montana 5th 3-6
1983 GB def 21st, rush (att 23rd, TD 17th) Dickey 8th 8-8
1986 Buf def 23rd, rush (att 25th, TD 23rd) Kelly 8th 4-12
1986 Mia def 26th, rush (att 31st, TD 23rd) Marino 2nd 8-8
1988 Mia def 23rd, rush (att 28th, TD 19th) Marino 10th 6-10
1991 Mia def 24th, rush (att 25th, TD 22nd) Marino 7th 8-8
1993 Atl def 28th, rush (att 26th, TD 26th) Hebert 10th 6-10
1994 Atl def 21st, rush (att 28th, TD 22nd) George 9th 7-9
1994 NO def 26th, rush (att 27th, TD 17th) Everett 5th 7-9
1996 Bal def 28th, rush (att 24th, TD 16th) Testaverde 5th 4-12
2004 Min def 28th, rush (att 28th, TD 29th) Culpepper 2nd 8-8
2011 Dal def 25th, rush (att 24th, TD 30th) Romo 4th 8-8
2012 NO def 28th, rush (att 29th, TD 21st) Brees 8th 7-9
2012 Dal def 29th, rush (att 31st, TD 27th) Romo 10th 8-8
2013 Dal def 26th, rush (att 31st, TD 18th), Romo 8th 8-8
2015 Det def 28th, rush (att 30th, TD 24th), Stafford 9th 7-9
A lot of bad defenses and unproductive running games there, and no winning records to be found.
In 2012, the Cowboys became the first team with these kinds of numbers in consecutive seasons. In 2013, they became the first team with these kinds of numbers three years in a row.
Marino and Romo are the only QB to have played on this kind of team more than once.