The plot/writing is just straight up stupid. If someone acted like Don in a marketing meeting the clients would be like "what in the fuck are you talking about?"
Then you have the obvious heavy handed feminist messaging. "Boy I sure would like to work, but I have to be a goood wife and stay home while my husband cheats on me" wife turns to camera "cause the patriarchy"
And then they try to paint Don as this cool customer who is the pinnacle of suave, when in reality his character is just a straight up goober. He's weird as hell, and comes off dumb as a box of rocks.
I just don't don't get it. My theory is that no one actually likes the show outside of internet people and people in the entertainment industry.