MSP is definitely a dated design. There are far worse airports in our network, but there are also many that are far better. MSP has a lot of glitter adorning an inefficient design.
And, god, the bathroom situation is awful. Worst just about anywhere. A fraction of the size needed for such a busy facility. And trying to get kids through them is a nightmare.
What I wouldn't give for a facility as state-of-the-art as DTW, or ATL.
To say that there's no reason to expand because of some kind of inevitable economic downturn is really just specious opinion. There's no sign of that, and great cities tend to attract and retain jobs no matter what. Most studies show that while companies really like extracting tax breaks from municipalities, in the end they locate where they want to locate anyway, whether they get the breaks or not. But by this line of reasoning, I suppose we should give up on SEA, and NYC, and SFO, and the list goes on and on with many thriving communities.