RIISE, his job is to present the show, make it accessible for all viewers. It has to be relevent as well. A casual viewer or someone new to F1 wouldn’t appreciate the presenters bleating about previous seasons and drivers unless it is actually relevant to the forthcoming race. He works for the BBC so you have to expect him to tweet about that kind of stuff.
Anyway, if you don’t want to know about his nocturnal activities, don’t read his twitter.
Plus, the goal of a presenter is to make everyone else look good. He has to ask questions to Eddie Jordan and David Coulthard that allow them to demonstrate their knowledge and insight. For instance, if they were talking about tensions in Red Bull Racing, a good presenter would say “Eddie, as a former team principal, how would you have handled the situation going on at Red Bull.” A bad presenter would simply state their opinion.
Let’s not forget that he does it all live, there’s no undo button for mistakes, and he has to cover up other peoples mistakes. He does an excellent job.