Property tax is intended to fund the local government. It doesn't care if the land is just being held as a hedge against inflation, or if a foreign investor is using the land to hide assets from their own government.
I suspect the claim of community benefit from stores, such as a bookstore or a coffee shop, is highly overstated. There's a drugstore within walking distance from my thousand-person neighborhood. It closed recently. Granted, it was a Walgreens, but the number of clients was so low the Muzak was crickets.
I think the only viable businesses left in the neighborhood are a sub shop and a liquor store. Even the gas station is pretty low traffic.
There's a lovely little coffee shop within a couple of miles away, close to the city center. It has nice events in the evening, such as trivia nights, contest nights, etc. Plenty of parking. But do I really want to go to where almost everybody is on their phone when I can stay at home and pet my cats? I think that's one of the major competitors' stores have, especially small, targeted-audience stores. Home is much more comfortable and rewarding than going out, especially if you have a cat or a dog.
I suppose the model sucks because the community is highly benefited by a low profit cozy coffee shop or book store, which might not be able to afford the property tax rate needed to discourage the "keep it vacant" strategy.
Maybe I changed my mind, and "vacant and/or not being used for its zoning purpose" needs a separate, additional fee.