One take on McDonald's and history - Someone might try to waymark or visit all the film locations of the documentary, "Supersize Me." (and get a bonus, since these waymarks could be logged in as movie locations - unless only fictional movies count).
I have 1 logged as a waymark, and there will not be more than a handful. Those that seem to be looking at McDonalds and other commercial waymarks are missing the other major listings in the other divisions, such as Buildings and History/Culture. Those 'in the game' understand the sheer number of waymarks that aren't of the McDonald's/Burger King/KFC mold, but perhaps a few numbers help others understand the postings being made.
I count about 22,000 WM in the Business/Commerce division, of which 14,685 are food/drink, and 5,302 for the stores/retail category groups (roughly summing up the waymarks in the subcategories list), both of which have a mix of big chain and independent operations. McDonald's currently has 2,151 posted WM.
The Buildings division has about 30,000 WM. This is a listing that would attract a lot of people interested in architecture and history. The top few subcategories are the category groups government services (12,213), religious buildings (5,798), transportation (buildings) (1,852) and meeting houses (1,389). OK, so many post offices are just modern brick and glass structures or are part of a city block. However, some others have interesting architecture designs, such as many built in the WPA era.
The "mother lode" where waymarks are posted is in the History/Culture division with about 42,000 WM. The top subcategories are the category groups and categories, historical markers (23,505 - which, by the way, is more than the entire business/commerce division), U.S. National Register of Historic Places (7,803 - a single category - impressive!), U.S. NRHP contributing buildings (1,442), Highways and Byways (1,442), American Guide Series (1,190), and First of Its Kind (1,070).
So, there seems to me to be plenty of non commercial waymarks being posted. Perhaps there have been more commercial categories posted of late, but as long as we keep adding non-commercial ones, too and have the ability to filter for the ones I want, I'm not concerned about that. I just don't want to see the day when I click on a waymark that a pop-up screen opens advertising the place.