Why aren't there pirates, spaceman and knights anymore

Hey, I've been out of the LEGO-world for quite a while (let's say since early 2000's), but now my kids are gaining interest in LEGO. So I was rebuilding some of my old sets with them, i.e. 6076 Dark Dragon Den, or 6270: Forbidden Island; ... Since some birthdays are coming up, I thought it might be fun to buy them a new set. But all the sets I find seem to be part of some franchises like Harry Potter, Pokemon, One Piece, ... not that I dislike them per se, but I do like how they use their...