I agree with what they said! I find that my family can do SO much during the first hour that a park is open, and it's almost doubled if it's EMH. Many people have the opinion that they're on vacation, so they're sleeping in and enjoying a leisurely breakfast. And if that's what their idea of vacation is, more power to them.
For me, I'm always awake by 6:30 anyway, so I feel like I might as well enjoy the empty parks.
Some examples of EMH (mornings) I've experienced.
Magic Kingdom: Rode space mountain, stitch's great escape, buzz lightyear, Indy cars (actually, one half did the cars, the other half did space), Mickey's Philharmagic, Pooh's Adventure, Peter Pan's Flight. No wait on anything! We literally walked from ride to ride. And even once the park was open, things were pretty quiet until about 11:30.
One particular magical EMH (back when it was EE), I had my son with me who was about 3 at the time. Space Mountain was having technical difficulties (no big deal for me, since DS was too little for it!), so they opened up the ToonTown area (whatever it was called at the time, it's where Mickey's house is). Most people weren't aware that it was open, and Mickey was just standing in front of his house with NO ONE around. He gave my DS a personal tour of his house, which was just too cute for words. Fewer people means more opportunities for extra magic!