I don't see it quite the same way. I don't think DIK affinity automatically makes someone a "bad" guy, but I do think it leans towards that in a way CHICK affinity doesn't. (
Though that is arguably a result of how poorly realized the whole affinity system is in the first place.)
In the case of Tybalt, it's a matter of proportion. For all his lying, manipulation and condescension, the guy is zero threat. His vendetta against the MC accomplished nothing more than ruining the mansion's ground floor (and potentially his teeth). His first "date" with Jill would probably have torpedoed any chance the guy ever had with her even without Bella's interference. Hell, his whole master plan amounts to little more than wasting ~8 hours of Jill's life. Tybalt is
useless, and at a certain point that becomes a problem.
Just as an adult humiliating a young child will always look bad no matter how big a brat the kid might be, the MC really shouldn't keep wailing away on Tybalt like this - not unless Tybalt manages to win a round or two against him first. You can say that's unfair to DIK affinity to punish them for taking DIK options, but I'd say the real mistake was framing DIK options as being so disproportionately cruel. I'm not saying Tybalt should be "redeemed;" I don't think that will happen and I definitely don't think it needs to happen. What I am saying is that Tybalt could become unintentionally sympathetic if the MC keeps tormenting him like someone pulling the legs off an ant.
On top of that, there's the fact that Jill, at least as currently presented, seems like exactly the wrong person to see the humor in the MC running up the score this way. Some girls could' Quinn, for example, would probably be a little too enthusiastic for my taste. But Jill isn't wired that way; if she were, there would be no need for this charade because she'd have slapped Tybalt and told him to fuck off a long time ago.
Jill can't simultaneous be such a pure and innocent soul that she refuses to trust her lying eyes but ALSO chuckle at the MC repeatedly making Tybalt suffer long past the point where he could offer meaningful resistance. To me, that smacks of protagonist centered morality. In theory Jill's arc could involve her rejecting that naive innocence and deciding Tybalt really does have it coming. But arcs in this game have been very slow so far. The longer we see the MC extract revenge for offenses Tybalt couldn't hope to inflict with both hands and a SWAT team, the harder it will be for Jill to credibly conclude he deserved it.
So yeah, unless Tybalt becomes a legitimate threat (and I think that ship has sailed), if the MC keeps this shit up it should cost him a shot at Jill's path. But that doesn't mean I think she should simply dump him without warning. What I want to see is for Jill and a DIK-ish MC to grapple with their different personalities. That's where I think things like the jealousy stat could have beneficial side-effects. As Jill can say, pursuing a DIK MC isn't the storybook romance she expected. But the fact that she's torn up about it means she must care about the MC.
So why not lean into that? Let a DIK MC and Jill explore what they like and dislike about each other. Let them try to work out ways in which each can change to give them more common ground. Do "Grease" without requiring the characters pull the full 180 in the last second. If an MC insists on doing everything his way, yeah, Jill will ultimately write him off. But if he's willing to reign in his excesses a little, then he can encourage Jill to come around and recognize why Tybalt is so loathsome in the first place.
No idea if DPC would actually do something like that, of course, but that's the only way to salvage something worthwhile out of the whole Tybalt mess. And I think it has the potential to be a lot more involving than the simple storybook romance the CHICKs would get.