Bottom line, obese person looks better on a bike than they do on a barcalounger.

When I see a portly person puffing up a hill (or walking bike up a hill) I cheer!! That's someone trying to get healthy. and that's grand.
Really, who gives a @#$@%$ what others think. you're on that bike for YOU. It would be silly to cover up with sweatpants when someone has designed clothing perfect for riding on your bike!