The build-up for Waltz as Blofeld in the previous film worked well, but it was a strange choice to just bin him completely. I guess it would have been a long time from Spectre to whenever another is, but it seemed part of a pre-set plan to 'end things' - Blofeld, Bond, someone else as 007. It all just felt heavyhanded.
I agree that Malek wasn't really convincing with whatever caused him to go postal, but I thought he looked too young (and got argued at here about it!). Bond films are almost always about the villain, and the strange whispered performance just made me think of a poor imitation of Bardem's grotesque.