Well, before they were busy working, as well as trying to maintain a personal life. They're not our dance monkeys.
Now they can afford to do it because a. Most aren't working, b. They're having plenty of time for their personal life.
I really fail to understand that kind of cynisism towards actors and filmmakers. They do their jobs, which is acting, directing, writing, producing, etc. Aside from that it's not really up to them to make people "feel special" or loved.
If they do that, that's fine and cool (some are more comfortable interacting with fans than others), but I don't condemn those people who just want to work on movies, promote them and then live their lives, instead of having to pretend to be your special celebrity online friends.