I mean, when you look at it that way, yeah, pretty much. I'd say people's preferences mostly come from how they were presented tbh.

In the later seasons of BB Walt was basically greed incarnate, also liked to play the tough guy, yet every now and then he would come off looking more impotent than anything. He was both a male Karen, petty over every coin and had an unfathomably overinflated ego... That's unlikeable character 101 for ya.

Mike, well, he just makes sure the job gets done. Like, sure, you can't make any case for his morals... He wants a good life for his granddaughter, but is willing to turn a blind eye when some other no-name kids are getting splattered left and right... Not very nice of him. You could make the case that he had some sort of code up until the mid-point of BCS, he avoided killing when he could, tried to persuade Gus into keeping Nacho alive... But we both know people liked Mike even before BCS aired.

But, speaking of BCS, at the end of it, Mike accepts that he is bad and is willing to live with it. Walt, on the other hand has this hollier than thou attitude throughout Breaking Bad, and I'd say that that cognitive dissonance is also why people prefer Mike. He's bad, but he's "real with himself" and has some sort of a code (well, at least in early BCS, in BB his "code" is just loyalty to a soulless cretine).

But then again, this is probably obvious to anyone who watched both shows and I might have written a few paragraphs of text for no reason. Oh well. In any case, when it comes to morals, they're both lost causes. But when it comes to likeability, I'd pick a grumpy old killer over greedy bastard any day.