Yes, for a lot of reasons. We go to enjoy the seasonal decorations. We go for TS and QS lunch/dinner which are often discounted for people with APs (or TiW), and we go to look at the resort specific items in the shops.
Why wouldn't we get free parking at the resorts, since we already get free parking everywhere else? I have no problem charging people to park at resorts who aren't there spending money in some way though, even if they have an AP. We don't need to park at a resort and go to the parks, we can already park at the parks for free. The only drawback is people who pool hop. We don't do that ourselves but I can see it being a problem, so if you have an AP (or not) and are there without buying anything, charge them to park.