The thing is, the extra parks were created in order to sell you multi-day tickets with the extra days at approximately half price. And what they give you for your half-price admission is ... half parks.
It's sounds fair that way, or at least reasonable. Assuming that it takes about $100 per guest per day to operate MK and Epcot and make a healthy profit, they've built DAK and shrunk DHS to the scale of the $50 or so they're getting for each guest who visits them.
The trouble is, the entire selling point of the multi-day passes is that you're getting FOUR (4) PARKS at a discount. The official message is, wow, we're giving you discounted tickets to 4 parks ... each of which is a great park. But they're not giving you a bargain. Maybe they're not even sure how to build and operate 4 equally great parks, with discounted tickets, and still make money on volume of guests or on hotels, meals, shopping etc.
The trouble is, the reality doesn't match the hype. You're getting value for the money, but the unfulfilled promise of "even more" for your dollar leaves a bit of a bad taste in your mouth. Hype is a synonym for exaggeration, and exaggeration is technically a form of lying.
Disney will never change the hype. They will never stop offering discounted multi-day passes. They will never "finish" DHS or DAK to make them the equal of Universal Studios or Busch Gardens. They will instead keep the big capital investments as delayed, stretched out and prolonged as possible. They will close some attractions and let others decay to irrelevancy in order to keep operating costs scaled to the revenue from discounted tickets. That's why you hear vague announcements that "big additions are coming" without any specific promises of attractions, completion dates, concept art, etc.
Will the public accept being lied to if in the end they get decent value for their money? Yes. Will they complain about it at the same time? Yes!