Agreed, there is no "actual" need to readback QNH with the ATIS code when checking in with approach. I would say that need there is a genuine need to give QNH on requesting departure clearance etc as not all places give QNH with taxi instructions and this could be the only QNH x-check before departure.
- I'm a little confused. My comment was about giving QNH on contact with 'Departures', not to approach.
I cannot follow the logic of your post on departure calls? The check-in with 'Departures' where an ATIS code is given (with or without a QNH statement) is certainly not the "only QNH x-check before departure" since any change in QNH from that of the QNH given in the code you announced to departures would automatically be given to you by ATC at an appropriate moment?
Anyway, back to DP - I'll see what our 'trainers' have to say about where this is creeping in from.