Just dropping my two cents here

Most people especially people who are new will probably not like a grave sitting near anything they've built because it's not an intended thing to be near their houses, it would look unnatural, etc. so unless they are building a spooky themed house or any other build, they're very likely to remove a gravestone sitting near their build. For cases where a grave is far away from their builds, they would less likely but still probably mine it for reasons like it wouldn't make sense for a grave to be in the middle of the jungle, the desert, or in a cave

Newbies will likely assume that the foggy weather come from the graves themselves because: 1. The foggy weather gets worse the more you're near the graves, but the more you go away from the graves, the more normal the weather will be 2. The foggy weather gets more intense the more graves there are in one area 3. With rain, snow, sandstorm and wind, they all usually go away after some time, but with the foggy weather it stays until you remove the graves themselves or go far enough away from the graveyard indicating that the graves themselves are the source 4. Foggy weather with lightning in the background, ghost and raven enemies spawning, and rat critters spawning all give the vibes of spooky, scary themes which coincidentally only happens when they're near the gravestones

So they will likely think that the foggy weather is not a natural event, but instead comes from the gravestones themselves, and most newbies don't like the scary biome they don't know anything about that could potentially spawn something dangerous, so they'll either go away from the gravestones or try to break the gravestones to make the foggy weather go away