The park is a full day park if you haven't been there ever (or haven't been there in a while). I go every trip and still find stuff to fill the day. This last trip, the Launch Bay and Star Wars shows were new to us, so that filled a big portion of our morning, but going with an infant and 4 year old, only 3 of the 5 rides were even an option for us.
So, I purposely planned hopping to MK after lunch. It "felt" less crowded at MK then DHS.
The problem is that the "space" of the park has shrunk considerably and thus it just feels crowded since the walking areas of the park were cut in half.
The other problem is that some people just like rides. Because everyone gets Fast Passes for the rides, and because shows don't interest a lot of people, the timing doesn't work or because they are "one and done" for a lot of repeat guests, the rides queues are just long. So there is only FIVE rides and you can only get a Fast Pass for one of the big ones (RnR, TSMM, GMR), so thus the lines for those 5 rides can always be pretty long (for example, I had to wait 30+ minutes to get on Toy Story Midway Mania DURING a morning Extra Magic Hour). But everything else felt not very crowded, the meet and greets, the Launch Bay, restaurants.
Losing Lights, Motor Action and the Backlot tour and the Streets of America and the Honey I shrunk the Playground, while "not much" still shrinks the capacity of the park into a small area and very few attractions.