All of those "expansions" added very little attraction capacity overall, which undermines your point. I'm pretty sure EPCOT will have actually lost attraction capacity even when everything is open.
They have absolutely spent money, though. They just haven't spent it very well (Toy Story Land...) or in ways that really help capacity, with a few exceptions. Not that adding restaurants/shops is bad -- those also help round out the experience, and people need places to eat. But the parks desperately need more attraction capacity and they've done far too much replacing rather than expanding.