The idea that Marvel should pass over him in favor of an obscure 2nd tier replacement character from an alternate universe, or recast him into complete unrecognizability is absurd and frankly offensive.
If I cast Chow Yun Fat as Luke Cage, you'd howl, and rightly so. Jeff Daniels as The Black Panther? Peter Dinklage as Colossus? Hulk Hogan as Puck? Charlize Theron as Storm?
Stunt casting is never progress. When an NBA team recruits a little person to play professional basketball, that does nothing to advance people of small stature. One reason the Greens can't be taken seriously is that every four years they nominate some celebrity who's never been associated with the party as their presidential candidate. Nobody respects that. That's why they're still a joke.
No, Donald Glover, as fine an actor as he is, can't play Peter Parker, any more than Logan Lerman can play Sunfire. Race matters. It defines our identities and -- and I don't like this any better than you do -- our opportunities and the way the world sees us and the way we see ourselves. If Glover played Peter Parker, he'd no longer be Peter Parker. He'd be an entirely new character whose entire life would be different.
Example: Peter Parker, his parents dead since he was a toddler, was raised by his kindly, grandparently Aunt May and Uncle Ben. When a little white boy without parents is raised by elderly grandparent figures, you get one mental picture. Now, what's the vibe, what's the impact, when the parentless boy raised by proxy grandparents is black? You're getting a whole different set of associations.
But, let's be clear here: the fannish clamor to get rid of Peter Parker as we know him for diversity's sake is just one more in a decades-long series of disrespects the greatest character in the history of superheroes has endured. He is, after all, the most fundamentally idealistic and decent character ever, yet Marvel had him literally make a deal with the Devil to expunge his marriage from existence because -- and I'm not making this up, it's what Marvel themselves said, only phrased more bluntly -- they couldn't figure out how to write a married character as likable and relatable -- at the time when he was more popular with audiences of all ages, kids included, than he'd ever been.
He's been replaced by a clone, replaced by Doctor Octopus, replaced by Kraven the Hunter, rebooted in a cynical, dumbed-down universe...
So maybe I should be inured to the greatest character comics has ever known being treated like shit.
But I'm not.