But you are not really adding any length to the season and compromising quality by adding one more team from each conference. Wildcard weekend is replaced by the first round. The net effect is one more team gets in and one less team gets a week off. Oh and the additional team to make the cut wont be an 8-8 team. This scheme would still allow an 8-8 division winner to get in but it would allow for the team that finished 3rd in their division with a 10-6 record to have a shot. The team that we all would agree should make it in over the 8-8 div winner.
and to take it a bit further, the only 7-9 teams that make it to the playoffs are division winners.
ref: seattle in 2010. there were 2 teams in the NFC that year with 10-6 records who did not make the playoffs (giants and tampa). meanwhile the NFCW who had no teams at all with a winning record got to send one.