On the other hand I don't see how inexperience makes woman feel uneasy.

Of course a man's inexperience can make women uneasy, and for reasons they might find hard to articulate if they don't encounter enough inexperienced middle aged men to form a good profile about them. Men who got their sexual experience at an appropriate age develop what I call the Adult Man's Skill Set (AMSS); yet ironically they don't see what AMSS does for them because they lack perspective on it and just take it for granted, like learning how to drive as a teenager. I, by contrast, can see all kinds of nonobvious things about AMSS from its absence in my life.