I don't think putting clothing on a dog is mean, as long as:
(1) It's not >80 F outside, and
(2) Your dog does not try to take the stuff off.
My dog has a number of sweaters, jackets etc. for when the weather is cold. Today it's -6 F; for him, "cold" is below 60 F as he's very small and does not have much hair. Right now he wears his fleece jacket 24/7. He is very excited when we "dress" him and he never tries to take it off.
My Beagle loves to wear something in the winter time. :) Like everyone has said, if they don't fight it and they're confortable your not doing anything "mean" at all if not doing something nice for him. :)
A dog is the only thing on earth that loves you more than he loves himself. - Josh Billings
I put a coat on my Chi. She has just gotten so she will tolerate it. It is just too cold outside for her to go out without it. I tried putting boots on her though, (small dogs can get frostbite very easily) She really hates the boots, and I don't dare take her out, to walk her when it's 20 degrees out. So, I made a carpeted dog walk in our garage, she loves it! So dressing your dog, for the comfort of the climate. . . there is not a thing wrong with it. It's like making a child wear warm clothes to play in the snow, even when they don't want to! (I just can't get her to walk, with her boots on)