Do you spend all of your time in the parks? There’s so much you can do in the resort itself to get away from crowds.
I think the dissatisfaction with crowds may also have to do with where people live or their other non-Disney experiences.. there’s not too many “amusement” places to go where you won’t experience crowds. I also just don’t remember Disney World ever not being crowded.. even as a kid I remember waiting in line for Space Mountain and Haunted Mansion in what seemed like forever.. and starting from outside of SM.
Or maybe..I think some of us, myself included, just change when we get older.. we become less tolerant of crowds.