Exactly. Epcot has almost no capacity issues because most of it's attractions have high capacity and load quickly with the only real exception being Soarin' and even that has a fairly high capacity.
M:S can load 40 people on each side every 5 minutes, which is pretty good.
SSE and Nemo are omnimovers that load constantly. UoE has huge capacity per show and is a great people eater, especially during the summer. TT breaks down a lot, but that's just because it's a very technical ride with an outdoor sequence, causing weather to be a factor. When it's working fine, it loads rather quickly with 8 cars of 6 people being loaded at a time.
Case in point: Epcot doesn't have capacity issues at all. It does need improvements to draw people in though. I still say an Imagination overhaul and a new E-Ticket to replace WoL (Tron?) would be excellent additions and make an already great park even better...
Oh, and did I mention that Epcot is the 6th most visited park in the world? DHS and Animal Kingdom are 7 and 8 respectively...