cash in fist: NFL stats have ALWAYS been recorded as single-season records. there are many reasons why this was done, but for a glaring one i can give you this: number of games played. Say you are a great player on a crappy team... should you be limited from ever appearing in the record books because your team doesn't make it to the playoffs? Look at LT in '03 - snubbed from ProBowl because his team was 4-12... yet he had amazing stats. Is it fair to rate other RBs over him because they played throughout the playoffs and got more yards? its not. LT had more rushing yards that year than many playoff team RBs... but the playoff team RBs had more yards if you add the playoff games.... this doesn't mean they were better, just had more opportunities... not everyone gets to play in playoff games, so the playing field is NOT even... not fair to all players.
second, stats have ALWAYS been recorded as regular season-only.... if you were to change that stat, you would have to go back through over 50 years of recordkeeping to change everything.
what you are saying, yes is technically true, but for all intents and purposes of record keeping, it is NOT true.
the rules have always been regular season - makes no sense to change it to something in your favor for your QB.