OK, clearly the square footage of my house is one of these things everyone's supposed to know and I don't, like my shoe size. (Seriously, I hate buying shoes so I can never remember - by the time I get the next pair the size label has worn off the previous one. Shoe store owners all over the city think I'm a complete moron.)
Our house is small but open-plan - people always comment on how "big" it is when they come in, because it looks way bigger on the inside. Like the Tardis.
I didn't mind moving into a significantly smaller house from our previous one, but I will say this:
-I NEVER want to live in a house with a tiny kitchen or insufficient bench space. In a good kitchen, I adore cooking. In a small, nasty one, I never want to set foot in the place. For those who don't like cooking to begin with, I imagine a smal kitchen would be even more offputting. We rejected SO many houses that had pathetic little one-bench kitchens, most of which bench was taken up by the sink. Hate, hate, hate them.
-I sew, which is a fairly space-consuming hobby. As hobbies go I'd hardly call it anti- the simple life, but it does take up space, particularly my fabric stash. I suppose some people would find it simpler to lose the stash, but I find it makes my life easier to have fabric to work with when I need it (and bought when we can afford it, hah!). I find good, really cheap lengths of fabric at the op shop occasionally, I'm not gonna leave them there.
So, if you do any kind of hobby that uses a lot of stuff - scrapbooking, woodwork, spinning, whatever - that'll necessitate storage and possibly work space. I don't think I could fit in a really tiny home because my hobbies include reading, cake decorating, sewing and cooking (ie a fair bit more kitchen equipment and random ingredients than the average person has). I don't think it makes you a bad, materialistic person to have hobbies, and it'll drive you nuts if you have nowhere to put your supplies.
-Built-in storage really helps. Our last house had a built-in bookshelf, set into the wall of the hallway. Ugly as sin, but SO useful. When we moved we bought a new bookshelf, but I still have some books packed away in boxes because they won't fit. (And yes, I do miss them and don't wanna declutter them!) This house, fortunately, has window seats with storage underneath, which I use for storing things like sleeping bags and bags of DD's old clothes for a future baby.