I personally don't like M:tG settings because of a few reasons:
- They're cash grabs.
- They're trying to combine 2 different cosmologies into one thing, which I absolutely despise. If Ravnica never had the Outer Planes or a crystal sphere in their lore before, why do they suddenly have them now? (I can answer that, because they want to make more easy cash-grabbing M:tG books in the easiest way possible.) Greyhawk and Forgotten Realms don't have planeswalkers, so don't try to fake that they do.
- Many of the worlds don't function as D&D worlds, like Ravnica or New Phyrexia, IMHO.
- M:tG storylines move much quicker than D&D ones, so it's harder to keep up, and there's a bunch of convoluted lore. (Same problem as Forgotten Realms. We don't need another Forgotten Realms.
I just don't think a lot of them work as D&D worlds. A lot of them have good themes, but their timeline progression, and how often M:tG blocks are released, and all the planeswalker nonsense makes things unnecessarily complicated, IMHO.
Feel free to comment and tell me I'm wrong. I like Theros, but would've preferred a plain Greek myth to D&D 5e book, but this'll do. I honestly couldn't care less about Nylea or Heliod, but I do like greek myths. I have a connection with Posiedon, Artemis, and Hades, I just don't have that with the Theros gods.