He's fine, the character is just written poorly.
I liked Spectre just fine but even I thought Blofeld was ill-conceived.
That said, as long as he's there, may as well make use of him if Fukunaga has a good idea for him.
Depends if Fukunaga has any say in the story. Isn't it the same old writers again. A good director doesn't really make or break a Bond film.