I think a loss is healthy. The Packers came down to earth, realized they'd better tighten up or they'll get knocked out of the playoffs, and are ready to win now.
I'm sorry, but that's ridiculous. There is no such thing as a good loss. I've participated in competitive athletics my whole life, and I can not remember a single loss where, in retrosepct, I would say I am glad I didn't play well enough to win.
That's like saying "It's a good thing I wrecked that car. Now I know not to turn left on red, and I'm ready to never wreck a car again.". Get real. Why would you ever want to lose? They don't get paid to perform in a subpar manner.
Well, it's not ridiculous, I've also played in competitive athletics all my life, and there are DEFINITELY games I look back on and say, it was probably good for our team that we realized *insert whatever we realized, whether it be we need to pass more, play more aggressively, etc.* And for a professional team, learning in the preseason a whole that you can cover is a great way to improve.