This isn't in direct response to the OP. Just a general musing about this topic.
I work in a Broadway theater. It amazes me how many people are surprised by the long lines at the bathrooms (or bar) during intermission. People will say to me, "Can't they do something about this?" And I want to respond, "What's to be done?" We have 15 minutes for ~1500 people to take a break. These are landmarked buildings, which means they're old and you can't change much about them without having to file mountains of paperwork with the city. Each bar has 2-3 people working. How many more are we supposed to staff for a 15 minutes period of time?
Perspective is a wonderful thing. If you go into an experience understanding that you're not the only one there for a good time, and you're not the only one who needs to use the bathroom or buy a drink or see a show, then you'll understand that lines are a fact of life. Is it ideal? No. But are some experiences worth it? For me, yes. For others, maybe not.
Walt was actually known for not liking that famous photo of him under the
Disneyland castle with no one else in the park around him. (I personally love the photo.) He said Disneyland was made for people to attend, and that without people Disneyland is dead. I've taken that perspective into my trips to the parks, and it really has helped me cope with the mountains of people that are there with me.
Personally, I have switched from scheduling my trips around expected crowds to expected weather. Unfortunately, it worked best for my friends to go in September this year, but I'm now firmly a January-April tourist at WDW if I'm making the plans. (Disneyland has better weather at other times of year.) Heat and humidity do more to ruin a trip for me than crowds do. And weather, while unpredictable in its own right, is much easier to anticipate than Disney crowds. Crowd patterns are so different than they were 10 years ago.
All of that to say this -- if you properly prepare your expectations, crowd size doesn't have to ruin your trip. Pack your patience and have a good time!