I'd have to disagree with this as well, my experiences with RCL is all I have to go by but I will give my thoughts on that.Things that I think are probably worse on other cruise lines:
More smoking areas.
Drunk party people on the ship and in cabins.
Less safe for kids own their own.
Having to wait in line for a soda and having to pay and tip each time.
Smoking is allowed in the casino but that was the only indoor area where you could smoke as far as I could tell. I can avoid the casino, no problem. Outdoor smoking was the same, I could avoid it if I wanted to. I avoid it on DCL as well if I want to. FYI I do not smoke.
The worst drunk party I have seen was on DCL. People drink on RCL as well and I'm sure they get drunk but as big as the ship is we haven't run into them. On DCL the adult only pool often has people at it that are drunk. As far as drunk in their cabins, how would you know? I have never been able to tell who is and who isn't drunk in their cabin.
Less safe for kids on their own? I don't think any ship is safe for kids on their own. Your on a floating island with 6000 strangers. What could possibly go wrong on either brand. It's up to the parent of course, but I doubt one line is safer than the other. Look at the molestation by the office and a young girl that happened on the elevator on, I believe it was the Dream. It happens, don't think the Disney bubble will protect your child, that is just stupid. It doesn't. We have to protect our children.
Waiting for soda? Tipping? If you purchase a soda package you get a cup in your room on arrival. They have lots of Coke FreeStyle dispensers through out the ship and you just go to one of those and get your drink if you want one. Are you aware of how many options those machines give you? If you have ever used a Free Style machine you will know that there are about a hundred options. If you are at a bar and don't have your cup you can still get a soda, you have already tipped when you purchased your package so no need to tip again unless you want to.
I understand your points and that they are valid for you. They aren't for me as my experience has been different. We don't all like the same things, which is actually good.