Lots of folks seem to think that the body is quite poorly designed and that technology must come to our rescue. Bullshit, say I.
See here for a discussion of the need for a new kind of shoe.
I'm always skeptical when I'm told that my body doesn't work correctly as designed and that I need to spend money to fix it. You should be too.
We evolved without shoes. Our feet don't need them. Our feet certainly don't need the monstrosity of the MBT (or any similar shoe). It changes our gait. Is the natural human gait really so defective that it must be fixed? Did humans really not know how to walk until scientists in the 21st century taught them? Bullshit.
Now, I do recognize that society doesn't approve of bare feet in many contexts. I also recognize that feet do need some protection in a modern environment. I don't recommend that we all just chuck our shoes. But I do recommend that we wear only those shoes that mimic as closely as possible the bare foot experience. Trust your body. It's fine as is. You don't need to fix it.
Many praise the MBT or equivalent; they've told us what problems it has fixed. Please place this in context. The fact that they're better doesn't imply that the MBT is optimal. It only implies that it's better than what they wore before. Also keep in mind that the problems ameliorated by the MBT might well have been caused by the inferior shoes that most of us wear.