Well I didn't like him that much because he use to beat up on Roger all the time (in his early years)...but after Roger started beating him back... I had no opinion of liking or not liking Hewitt.
I had no problem with his 'come 'ons' because when he played Roger, he really didn't do it that much. Or if he did, it didn't bother Roger that much. The turning match was that Davis Cup match that Roger should have won but Hewitt came back. But I never held anything personally against Hewitt. I've seen worse on the court than him.
Now he's one of the 'elder' statesment, not winning that much, the underdog, settled, and all of these factors makes him 'likeable' to the average fan, I think. He's not 'expected' to win so more people root for him now.