Are you sure B and H were always non changeable on the day of departure? I distinctly remember paying a change fee on the day of departure to change departure times on B and H fares.

As in the other change of flight thread, the problem here is that BA is forcing many people who require a small amount of flexibility to pay for lots of additional flexibility they do not need. Many corporate travel departments will be unimpressed with the argument that a traveller needs flexibility to be able to return home early, flexibility to take a later flight is more understandable.

I would see this as a customer service/retention issue. If I manage to conclude my meetings for the day early, I would if at all possible like to take an earlier flight, but it would be unreasonable to expect my client to pay significantly more for my own personal convenience. In these circumstances I just tend to spend longer in the lounge unless I have a flexible ticket, but I would infinitely prefer to spend extra time at home rather than yet another airline lounge. I definitely take this sort of thing into account when I select a carrier and it is one of the reasons why BA is often low down in my preferred carrier list.