People have all kinds of expectations. But your title kind of acts like there is some universal rule that most agrees on and a lot of people try tries to follow.

That said, I do get the suspicion that a majority of females (which may be a small majority! nitpickers and poor readers beware!) prefer to have a male that is more experienced, whether they admit this to themselves, let alone others.

Males might have even stronger preferences, which are sometimes contradictory.

I think many people have some preference here, male or female. They all have some idea about what the sexual past of their dream partner would be. So yes, I would say it matters, to other people. But it shouldn't matter to you or influence your motivation in any way. You are who you are and people will (sometimes viciously) judge you for it, but there is just no way around it.