It is not only "cool" but it is completely and utterly within the rules. Why wouldn't someone grab their dream house(s) on another server?

It seems to me that those who refuse to create an alt on another server where they could reasonably acquire their dream house don't do it because they have no friends to show it off to. Apparently, those who MUST have a house to flex for their friends are the ones who are needing to be "cool".