Well that means someone like McNabb should be a HOF lock then
This is a bit of a strange example in my opinion. McNabb may well make it. But Romo is better statistically as a passer. Case and point this is McNabb's rank in passer rating through his career:
18,7,7,16,4,16,4,9,14,12,24
He only had four years in the top 8. This is his rank in YPA:
30,19,25,19,5,13,2,15,18,7,15
If you are curious here's Romo:
Passer Rating 5,5,8,8,4,10
Yards Per Attempt 1,2,6,4,7,8
The two areas where McNabb statistically had an edge on Romo are INT% and rushing. Romo is superior in pretty much every other category by a significant margin. In fact, I think ignoring playoff success would actually hurt McNabb's case a great deal. The crux of McNabbs HOF case is his teams made it to the NFC championship game 4 years in a row. Not his career numbers.