Regardless of absurdist action during Brosnan and such, 007 is supposed to be a suave, classically masculine man's man (for the market, that is). If a woman, she probably has to fit that side of spy tropes.
Now, the Rock is clasically masculine in other ways, but while I like him a lot, I've never seen him do suave well. He indeed has a range beyond campy comedy action stuff, but I'm not sure he'll be able to do the role well.
I'd love to see a nonwhite Bond, and I'd love to see a female one. Doesn't have to be pseudobritish martini tux guy every time. Would the market accept the Rock? Idk.