Right. I remember all that. But even before the NFL & AFL got together for Super Bowl I, the NFL (and the AFL) still had divisions (ok, conferences). Turns out that they've had'em since 1933, which I don't remember.
But look at the 1932 season: http://www.pro-football-reference.com/years/1932/
A 7-1-6 record tops a 10-3-1 because, I guess, ties don't figure into winning percentage. Whazzupwiddat?
And already, by 1934, with divisions, look at this: http://www.pro-football-reference.com/years/1934/
8-5 plays 13-0 for the championship, while 10-3 gets nothing. A wildcard spot would've fixed that!
Once you get divisions, you get playoffs, and it ain't ever going to be perfect all the time.