I think that it has everything to do with naturism, as it is an anti-clothing attitude. Nudity, nudism,and naturism are logically, or naturally the antithesis of clothing. Clothing is inherently generally bad socially, unhealthy, wasteful, insensitive, manipulative, restrictive socially, restrictive physically, false, false prideful, demeaning as a good nudist will point out. Nudism has a wisdom from experiencing the state. Clothing is immodest and naked is less so.
Is this a rant!?
Clothing bad. Protective covering good. Nude best. Burn the clothing! Hang the garment industry leaders as criminals and the dress designers! Liberate us all!!! Lock 'em up!...
... Zealotry is so much fun.....
So, my compliments on those quotes that you found from Mark Twain, Nuduke. Gotta wonder how that was received back in Victorian America. He was very popular, celebrated. His characters skinny dipped, hung out naked on the rivers. I think it was Huck that said that he wouldn't wear them at all, if he could. Hangout naked, smoking from a corn cob pipe.
Jbee