I think it's because he's a permitting near-empty vessel that Sheer was made house speaker. It was a way to give carte blanche to the Conservatives in the HoC. I think that the smile that so often dons Sheer's face is maybe just how he deals with not fully grasping his environment and what's going on around him - just smile and play along.
It's been said that you become what you hate, and I think the Conservatives just picked a leader that represents their ad hominem criticisms of Trudeau - which aren't really accurate when said about Trudeau.