Fans don't like the notion because a) not everyone should be able to go to the playoffs, it defeats the purpose of the playoffs and because 9-7 is mediocre. Mediocrity should not be rewarded.
So the 9-7 SB winning Giants are a mediocre team? And not "everyone" would have made the playoffs. if the Playoffs expanded to 14 teams this season you would have the 10-6 Bears as the 7th team in the NFC and the 8-8 Steelers in the AFC for the 7th AFC team this season.
Also you would have less teams give up so early in the season if they knew they had a better shot at the playoffs