I don't think we need significant rules around social interactions beyond what we already have.
Who is "we"? You and your players? If so, then fine, then don't use such rules. Continue on as you wish. I don't see anyone saying otherwise. If you perceive anyone else as saying otherwise, we should check on that and make sure.
If "we" is some other group, it'll bear some discussion as to whether it is fine.
So I'm not allowed to express a personal opinion? Because that's what it sounds like.
You're fine to express your personal opinion. But, if you ask one question, get an answer, and then proceed as if the answer was to a different question, there's a problem.
As far as design principles, I like what D&D does.
Which is, again, fine. You keep plugging away at D&D then.
I think D&D has done a dutiful job of having rules for its traditional main foci. But, if D&D was designed intending romance to be a major focus... it'd probably have rules for it, weapon speed factors and all.
We might infer from this that maybe you aren't really itnerested in a game with romance as a main focus. And that's fine. But then you're not really in a position to object to "for people who do want...".
What can I say? There is tactical thinking when it comes to some interactions.
In every game design, there's a choice for what interactions should have tactical thinking. D&D is largely a game about who kills whom, so there's a whole lot of tactical thinking around combat. D&D has chosen a focus where most conflict resolution is physical, and often violent.
But, we can imagine a game with different focus, say, less about who gets killed, and more on who marries whom. Mr. Darcy does not need a two-handed sword or magic missiles. He doesn't need rules for moving about on 5' map squares, he needs rules for wooing and social climbing.
Which is really to say, D&D-fantasy isn't the only genre out there. If it is your favorite, that's great.
However the moment you set up a framework for people to lean on, for me it would break immersion and limits options.
So, if you don't want limited options... why have a combat system? At this point, you know enough about game combat interactions to just.. narrate combats, no?
I've played in larps with such - narrative combat scenes, with no strict rules applied. Indeed, one of the most character-defining moments I've had in a larp was in a narrative combat scene in the first episode of a 5-year campaign. There's a lot to be said for it...
But, everyone wants D&D to have a robust combat system. Folks who want romance as a game pillar are also likely to want to have robust romance rules. And that statement doesn't equate to you, Oofta, having to use robust romance rules at your table. You get to continue to do you.