When a client bashes my design, I move on with my life and just do whatever they want. They're paying so screw it. All I can do is advise them as a trained professional, try my best to convince them, and then move on. If they're that adamant about what they want than that's what they're going to get from me.
Embrace your capitalist core. You're a business, why would it affect you to do what your client wants against your advice? As long as they pay I see no reason why they're poor judgement should affect me. Bash my designs all you want but at the end of the day - "F you"Too bad, pay me." And until they go with another designer or stop paying me I'd continue on that fundamental principal.
Henry Hill: [narrating] Now the guy's got Paulie as a partner. Any problems, he goes to Paulie. Trouble with the bill? He can go to Paulie. Trouble with the cops, deliveries, Tommy, he can call Paulie. But now the guy's gotta come up with Paulie's money every week, no matter what. Business bad? Fuck youToo bad, pay me. Oh, you had a fire? Fuck youToo bad, pay me. Place got hit by lightning, huh? Fuck youToo bad, pay me.
Oh that terrible design you were so adamant about didn't work out? In the words of Henry Hill, "F you"Too bad, pay me."