My wife wears a buff, sun gloves, long pants and sun block long sleeve shirt while fishing so she doesn't get burned.
I wear the same stuff for the same reasons not only while fishing but also while mowing. I hate sunscreen so this is my way around having to put the crap on.
I would bet 99.9% of people wearing the sunblock clothing are wearing it for that reason and not because they want to look like a pro.
If we look stupid so be it; We don't give a rats behind what anyone else thinks.