I agree that surroundings influence a person’s sense of comfort and well being on a really visceral level and it's not the same for everyone, in fact it isn't even always the same for ONE person!
Pretty much from the moment I left home for college I was forging ahead on my own, from scratch with nothing to define me except the boxes that I moved into my first apartment and my class list (in a strange town) life was thrust upon me. And it got more full, slowly at first... acquisition of furniture... pursuing a career... then it really got busy!... marriage... home ownership... 2 babies...
I needed my stuff, my stuff needed me - a cozy relationship.
Now at this present point in my life (approaching 40 with lightening speed) the opposite is true, clutter feels heavy like it will squash me and sucks out my freedom with every dust-catching surface, it's emotionally draining and "loud" all the time.
What changed? I have a theory that the more full and stable my life becomes, the less tangible affirmations (aka stuff) I need to define myself to feel confident in my own skin.
Perhaps that is part of what hoarding is about. I am amazed how many of the hoarders (on the TV show) started off as tidy people... only to suffer some tragedy that changes their needs. These people need to feel secure and search for the security with things, it's tragic how messed up (literally) the stuff made everything!
I was a packrat. One personal tragedy away from much worse habits... it's a reality that I'm okay with really. Through love, trust and self-realizations I have come out the other side with a greater respect for my things. Not so much of it means what it used to, and I honestly think that is a very very good thing!
Bravo minimalists for not needing the stuff to be happy. But please don't underestimate the genuine comfort a bit of clutter can provide for anyone that's feeling a bit lost.