No, those signs and pledges were not a joke at all. Back then, station owners, operators, managers, and yes employees had pride in their stations. I'm sure there were some restrooms that were not up to par, but they were the exceptions not the rule.
Now however, is a different story.

Looking for photos, etc from 60s era Shell-A-Rama gas station and Pal's Diner, Rt. 17 Mahwah, NJ
& US or state highway signs, shields, route markers