wbwood,
Never any intention of "jumping on you" and sorry if you took it that way. The gist of my post was that the entrance fees for Michigan State Parks is certainly not high compared to other states with entrance fees.
Something you may not know is that according to the Michigan DNR data info, between 24 million and 29 million visitors use the our 100+ state parks each year now. Roughly 92% of these visitors have purchased yearly passes or $11 when vehicle registering yearly. The DNR data collected places the estimates of non-resident visitors at approx 23%. That's around 6.5 million and they just keep coming back year after year like clockwork so they can't be too unhappy like the OP seems to be.
Data shows that the 32 Great Lakes shoreline state parks with CG's alone account for an average of 74% of the total visitors yearly. Grand Haven SP tops 2 million each year for No 1 and Holland SP just 18 miles south is close behind at around 1.8 million and in 2nd place. Michigan has so many state parks and they are large in size on average. 3 of the largest on Great Lakes shorelines are Procupine Mtns SP is over 58,000 acrea and Tahquamenon Fall SP is roughly 50,000 acres and Wilderness SP in the Lower Peninsula at over 10,500 acres. Hartwick Pines SP inland in the Northern L.P. is about 9,700 acres. Close to 300,000 acres of parks alone and 746 boat launches plus 16 harbors for refuge on the "Michigan" Great Lakes shorelines along with 61 other harbors on Michigan's more than 3,200 miles of Great Lakes shoreline. Only Alaska has more shoreline and very few people!
Is managing and maintaining all of this land, structures, and assets, etc expensive? You darn right it is and our state parks are operational self-supporting mandated by laws passed many years ago and they are beautiful and well used and yet well maintained! It simply takes money to do it!
You may notice that the state park systems that do NOT have entrance fees are financed by the state government and that money comes from it's taxpayers. At least, every state I could find that has posted their info does it this way. Some also have very high site fees to help offset the lack of entrance fees.
There's NO free lunch!