I have two little Disney fans, and I've more or less converted my husband in that last decade. Both my kids would like to live at WDW. We own DVC, we go to WDW every year, sometimes more than once a year. Neither my kids nor my husband hover on message boards reading about how much hasn't changed, or hasn't changed fast enough. Yes, DH has been known to wonder "aren't they done with that yet?", but really, even going every year, WDW still has a lot to offer. And I still manage to plan something new for them to try every single trip.
MK has more than enough to entertain us. DS (age 10) will tell you that he does not care about the NFL additions at all, although in actuality he has enjoyed most of it (although he refuses to do ETwB.) DD (age 4) absolutely loves everything about NFL. Everything. The must do areas in MK for my kids are Adventureland and New Fantasyland.
DHS was actually on the "eh, skip it" list for us for several trips. The only thing both kids could and wanted to ride was TSSMM, and before FP+ we were never there early enough to get FPs. As of this year, they can both do Star Tours, too, which helps make it a more fun park for them. DS liked the Playhouse Disney/Disney Junior show when he was little, and now DD likes it, and they both like the VotLM. They both like the playground. That's about the list of the things the kids wanted to do. FP+ actually put DHS back on our list for our trips, but even so, it's a short day for us. This is the one park that I agree should be an embarrassment to Disney. I am so glad they have a new vision for it, and are going to pump a lot of money into it. It needs it desperately.
Epcot was my favorite park before I had kids. However, the Epcot with truly amazing food and plenty of non thrill rides of my memories is long gone. (I still miss Horizons and the World of Motion. I do not miss Body Wars, which inevitably made me sick.) The kids don't have the patience for an afternoon wandering through shops and looking at displays in WS. But they love "the Nemo pavilion" and both rides in the Land, and they'll put up with Ellen for dinosaurs, and they've come to accept that Mommy is going to make them go on Spaceship Earth every single time we go to Epcot. And, for some reason, they love the Grand Fiesta Three Cabelleros boat ride in Mexico, which no one ever talks about as an addition of the last decade, but is far more engaging than Rio del Tiempo. (Although the last times we rode it, my kids were the only kids around and EVERYONE else was drunk adults. Go figure.) They are both looking forward to the Frozen Maelstrom. Making them pick between FP+ for Frozen and Soarin' is going to be a nightmare, however. My husband and kids like Epcot. We still find more than enough to do. It certainly isn't the embarrassment that DHS is (except for Captain EO, my gosh, just get rid of it permanently), even if it could benefit from some updates. Honestly, if they would either add a new "country" with a ride, or put a solid new ride in any of the existing countries, and redo one of the currently defunct pavilions using the Inside Out characters, I think almost everyone would be happy. (Ok, they are never going to make almost everyone happy, who am I kidding? But it would please many people.)
Animal Kingdom is already on the right track. We're really looking forward to the new nighttime safari and show. We can't wait to see what they do with Pandora/ Avatar. (The movie was fine. The setting is gorgeous. I am sure it is going to be a beautiful addition to the park.) I still wish they'd add Australia, or even the Americas, as a new land. My daughter wishes that the Pocahontas meet and greet would get FP+ because I won't wait in line with her for 45 minutes outside in the heat.
WDW is still wonderful to my family. I'm not someone who is happy about every decision they'd made about the parks. I'm not someone who thinks they can do no wrong. However, I do think they provide a solid experience overall, and that many of the projects currently underway will be good additions.
That said, we went to Universal for the first time a year ago. After hearing about how they weren't good for young kids for so long, we decided to try it out anyway, because we wanted to see Harry Potter. My kids LOVED Universal. (They did not love being woken at dawn to get dragged at a breakneck pace through a park they'd never seen to get in line for ollivanders, and then forbidden journey (which neither of them were going to ride.)) Universal may not have been good for young kids at some time in the past, but that is just not true any more. My kids liked their 2 days at Universal as much as WDW. DS doesn't like thrill rides, DD is too little for many thrill rides, and they still had an amazing time. Honestly, people who are telling you there is nothing at either Universal Studios park for kids have clearly not taken kids. The Barney, Dr Seuss, Curious George, and American Tail areas are NOT aimed at adults, let me assure you.

Both Universal Parks were great. My kids want to go back, and we're tentatively planning to next year.
Disney lost two days of our business last year, and they're probably losing two days of it next year. That's a pattern that's going to continue to be true. Every year or every other year, we'll probably spend a couple of days at Universal. That's a function of how good Universal is now, not a function of "how bad" Disney is. It isn't that Disney has lost our business, its that Universal has won a bit of it.