Well of course it's not a true must-win game since we could go 1-3 and win 12 straight and make the playoffs. It's not MY logic...it's a fact. I would say we definitely should win this game if we want a realistic chance at the playoffs...the Cardinals are one of the weaker teams we play on the schedule for the remainder of the season.
All I'm saying is to think every single game of the season is a "must-win" is extremely naive. The fact that there have only been 3 or 4 undefeated teams in the regular season in NFL history proves that. Every team loses games, it's just about winning enough of them to make it into the playoffs.
I think your statement must not have been intended literally, whereas I'm taking it as literal. Otherwise I'm not sure I follow your logic that every game is a must-win. There are only what...5 undefeated teams right now? So at least 7 teams who already have 1 or more losses will be making the playoffs. I feel stupid having to actually type this stuff out since it's common sense, but I'm trying to clear it up from my side.