Everyone is entitled to their own safety zones when it comes to their children. Each parent is clearly trying to make the best decisions they can to be the best parent(s) that they can.
IMO, and this is just me, there's a time and place for independance. When we go to Target, Walmart, Best Buy, Bass Pro Shops, or some other large, interesting store I allow my sons (ages 9 & 11) to go off together in the same store I am in as long as they have their cell phone and stay together. We even sneak around every now and then to check that they are staying together. It gives them the independant time and us a chance to see how well they listen and think on their feet. I personally wouldn't be cool with one of my sons going to DisneyQuest alone at this age or most likely 14 years old. DisneyQuest is loud, bustling, and has a lot of dark corners, etc. I would be afraid. Call me paranoid but I grew up in Central Florida. I have family who still live there. You should hear how they lecture me when I take my family to WDW now that I'm an adult about all the little "safe" things to remember. How many people walk out of their rooms on property in the morning anxious to get to the park in time for EMH or a Priority Seating and walk off before the room door has shut all the way and they have checked to make sure it's secure? Some pick-pockets are masters at what they do. In a crowded bus or line they could easily do the bump-n-grab technique and you would know nothing. And what better place for a pedophile to hang out looking for their next target than WDW where it's absolutely loaded with kids??? They don't have to snatch a kid and run out of the park with them. There are lots of corners, little areas they can take a kid and do what they please before you've even realized your child is missing. People on vacation let their guards down because they are in that "zone" of all things good in the Disney life. It's a fact that makes life easy for those seeking out the weak to prey upon be it theft or worse. If you think these things don't go on at WDW, think again. Do you really think you would know it if it did? How damaging to WDW business would that be?
My point is this: don't knock people for operating within their safety zones. Some are more cautious than others. Perhaps some should be more cautious than they are. It's not for us to judge each other. We need to take care of ourselves the best we can with as much info as possible. The OP asked for opinions and thoughts on the matter. Nobody here is right or wrong. They're just people entitled to their different thoughts and feelings. Different isn't wrong. It's just different.