Short answer, no, you're not wrong.
This was clearly an attempt by the drummer to take the band hostage. He attempted to seize the bandleader role when clearly no one else thought he should be bandleader. I agree that a purely democratic band can be asking for trouble. You need someone to set the tone and be the buck-stops-here guy. But at the same time, unless the band is how someone is paying their rent, band leadership is more like volunteer management than being the boss of a business. You can't give orders and expect people to obey; there's no leverage for that. You have to form consensus and make sure that what you're asking of people meets THEIR goals for being in the group. They have no reason to stay otherwise.
And also, yes, clearly an attempt to dodge having to learn new songs. I would agree, as a caveat, that I don't know if your existing set list was any better than his suggested one. If your list was incoherent or loaded with guitarists' favorite deep-cut wankfests that no crowd wants to hear, ever, then he may have had a point in saying you should change it. But as has been said, there are thousands of great songs in every genre and there's never a reason to insist that the setlist HAS to be composed of THESE 40 tunes and no others. His insistence on playing a fixed list with no flexibility tells me he was too lazy to learn anything new.
When I was putting Six Cowards together, I was in touch with a drummer over CL. Older guy, could sing, which would have been a great asset, and a good drummer. But I felt strongly that a band should be able to define its identity clearly, for booking purposes. We play modern alternative rock. He kept insisting that "you can't just do that, you HAVE to play classic rock as well." Err... no, we don't. I've been in plenty of this-n-that bands and they're almost always mediocre. He did not get the drumming position.
Another time, I started playing with a rockabilly band. I didn't have much background in the genre so I did some research, and I quickly realized that there are two different approaches, more traditional 50s rockabilly vs. contemporary retro stuff, psychobilly and all that. So I was asking which we wanted to be, and there was some divided opinion. I put some off-the-beaten-track stuff in an "ideas" folder in the band dropbox. The guitarist freaked out. Next rehearsal he said straight up that, basically, there was a lot going on his life so he just wasn't going to learn any new songs, period. The band was going to play the list that he already knew. That killed a lot of my interest, not so much that he wanted to keep it traditional as that it HAD to be HIS set list top to bottom, everyone else had to learn new songs but him. Even then I might have stuck around but he segued into a bizarre meltdown unloading on the drummer for no good reason. Good-bye.