I’ve heard the OP’s perspective before and it’s often because they don’t view Disney as a frequent destination. I would agree that for a once in a lifetime trip, a 6 year old will get more out of it than an infant. But a lot of us on here are regular visitors so we take our kids from a young age and go over and over again. I have 3 little ones and we took them for the first time at 10 months, 12 months, and 8 months. DLR was always the first trip for all of them since we’re in CA and we also have family in LA, so we would make it a road trip and both go on vacation and visit family. WDW first trips were at around 14 months for the first 2 and hasn’t happened yet for baby 3 since we don’t want to fly yet. We don’t have anyone to watch a baby for us while we vacation (plus I would hate leaving them behind anyway).
We are also DVC members and have APs for both WDW and DLR. Since we go frequently enough, our trips are on the relaxed side and we don’t do too much in a day. This helps us minimize any crying that might occur since we’re taking it easy. We stay in 1BR or 2BR villas, get groceries, and settle in for some fun family time.
After becoming a parent, I really saw how young a child could be and still have a reaction to a Disney trip (or anything, really). Seeing my 1 and 3 year olds laugh and clap while watching parades and shows are priceless memories for us as parents, even if they don’t remember it. I adore the photos of them in the parks when they’re little, and we’ll even book a local photographer to do family photos at our resort or in the park (so worth it!). Plus there are studies emphasizing how critical the first few years of a child’s life are in making neural connections, and I believe travel and all these new experiences are an important part of their development. We want to travel with our kids to Disney and elsewhere because we believe it’s good for them as individuals and good for us as a family.