It's an interesting point, indeed... "У меня в доме", "у меня в подъезде", "у меня на этаже" do sound a bit off... Well, the house is not only mine, after all; it's a big block of flats. But I noticed that I really prefer to use "мы" instead of "я" in many cases, even if it's really only "я".
I think it's a part of the language, first of all; gRomoZeka is absolutely right.
And still, I must admit that I am very, very individualistic, and, I hope, independent, too.

To me, one of the main distinctive features of Russian people is indiscipline. I'd even say that's our Russian form of independence. I don't mean that a Russian can't discipline himself, although it's open to question, too. I mean he can't be disciplined by someone else (and that's the thing I can definitely say about myself). You can't make bus drivers open the front door if they don't want to. You can't make clerical people and shop assistants smile and be polite if they don't feel to smile and to be nice with this particular person. You can't make a man go to work if he wants to go on a drinking bout. You have no power over souls and wishes of Russian people.
The European independence is reasonable and rational; the Russian one is turbulent and has no limits.

Probably I sound too apocalyptical, but that's how I really see it.