If by "countless times" you mean 3, then you're right. Plus last year, TB got in at 8-9. So 4 teams have won their divisions with losing records.
But here's the thing. That division winning team beat out three teams that essentially played the same schedule. That 3rd-place 9-win team in another division played a completely different schedule, with almost no common games. That other division probably had 3 winning teams because they all got to play a bunch of crummy opponents. So your proposal rewards teams for facing a weak schedule and punishes teams for facing a tough schedule, which seems like the opposite of what we should be doing.