HITW and TW are shows that had they aired on other stations would have done poor in the ratings.
The problem with the BBC is that they seem to have certain presenters that they desperately try to shoe horn into as many programmes as possible. How many flops has Graham Norton presented since his high profile move to the BBC, The bigger picture, the One and Only, the recent eurovision show, and arguably his BBC2 chat show which gets similar ratings to E4 and BBC3. The only success that comes to mind is the ALW shows.
Now ITV also have the same problem with Ant & Dec and Piers Morgan springing to mind but the concept of the shows are better. Also personally any programme with the title total(ly) is an immediate turnoff.
BBC have a strong Saturday schedule without the need for total rubbish. I can see the point of TW as it is a good filler ideal for the Summer Months where there is no point showing expensive dramas. For the rest of the year they can have Family Drama, Lottery Quiz, Casualty and Reality Show or Comedy to choose from.