Q: What are the arguments against a shared universe? Like, would Hawkman be tolerable if he wasn't standing next to Superman? -- @Dan_Toland
A: I gotta say, I am probably the last person on the face of the planet that you should be coming to with this question. Not only do I love the concept of a shared universe in general, but I love it specifically in how it's evolved to become a defining feature of superhero comics, to the point where it's actually as much a part of what I think of when I hear the word "superhero" as powers and costumes.
On the other hand, I am also a dude who has never passed up an opportunity to make fun of Hawkman, so allow me to answer that part of your question first: No. Nothing will ever make Hawkman tolerable. Hawkman is the worst.