Mainly because I have no reason to think they are finished. You can’t do anything interesting with them (stepping on to them does nothing). They’re one tile in size. They don’t even have their own unique sprite. They don’t spawn anything unique to them either.
Basically, for the same reason I think the “Netherworld Contact” lab is unfinished and should be removed until it is.
Think of it this way: Imagine playing a Super Smash Bros game with items on, and you grab a Pokeball. Generally, you could get any number of useful things out of that Pokeball. But instead, you get Goldeen, which is completely useless. That’s what getting the “Netherworld Contact” finale is like, and why I think it should be removed until it’s finished.