You are cost averaging, but the sites did not cost you 32.00. The site cost is what it is, and the pass cost is what it is, and the two are separate. There are a lot of people who visit state parks without camping, and if you bought a yearly pass, you can still go to other Mi State parks.
It is very common to have to pay entrance fees to State parks, be it daily, weekly or yearly. It is also common to charge more for non residents.
As an Illinois resident, I appreciate the opportunities for camping that are offered in Michigan and Wisconsin state parks. Most of the Illinois state parks that are equidistant are in pretty rough shape. And frankly, just not as nice. We also are aware that most states are experiencing financial crunches, and some of the planned updates and upgrades have been put off for so long in all of these states, electric is often old and can be iffy, sites were not built for large MHs and 5ers, and sometimes aren't level. And full hookups are a total luxury in public parks, especially in the midwest, where winterizing is an added expense best left to private park owners.
As an aside, winter is one reason that parks in these regions are hard pressed to update, since the only time that they can do so is in the spring through the fall, prime time for campers. In the south, updates can be made in the summer when there are fewer tourists. But for a state to close a large section of a popular state campground in the north is a hard decision to make.
Anyway, I understand if you were not happy, it happens even with the best places, one can't please everyone. I think that you ought to voice your opinion to the Michigan DNR, and on RV Park Reviews.