Mice often carry diseases [1]. When they get into homes, they can transmit those diseases to the occupants, which are often house pets, children, or the elderly.

Mice also chew holes in walls, cupboards, pipes, and wiring, sometimes to disastrous effect (e.g. house fire [2]).

You can pretend to be all macho and unconcerned by mice, but the fact is, they're awful disease-carrying rodents, and you ought to avoid them and get rid of them if they're in your house.

[1] http://pestcontrol.about.com/od/diyrodentcontrol/a/Rats-And-...

[2] http://pestusa.com/rodents-fire-hazard-considered/

I'm not saying I'm unconcerned by them, just that I do not believe they carry the same stigma as cockroaches or rats.

Of course, if the majority of people would see an actual mouse on their cupboard they would not be so happy - me included.