I agree this year is a crazy year for QBs in the NFL. A lot of starters have been replaced because of injuries, bad play (Manning, Keenum?), and retirement (Luck). Every week seems more unpredictable apart from the teams that still have their starters.
Cousins needs to play better, we all know that. But so does the rest of this football team. The Defense looked mediocre against the Bears 2nd string QB. The Offensive line was absolutely terrible (6 sacks allowed). Play calling and game plan was bad, which falls on coaching. The whole team needs to better.
Every team has a few big contracts that can be seen as burdens on the team. Paying Sam Bradford 20 million just to play one or two games comes to mind.
I haven't given up on Cousins yet. I think he can turn things around. The great news is that if he can't, he's only under contract for this year and next year. The Vikings will be able to move on from him in a year and some change if things don't pan out.
Give the guy this year. It's still early! We have time to right the ship. If we miss the playoffs again start getting excited about drafting a rookie QB to replace him.