What does interest me - in contrast to the other exec changes - is that this directly discourages people to fly BA.

The exec club changes discourage people from crediting to BA. Indeed - if you read the thread - of those threatening to leave a good proportion are considering migrating to another OW programme. BA win in this circumstance - yes - they still have to pay for your lounge costs - but the rest of it - the avios liability (for example) goes away.

This, on the other hand, appears to be trying to chase people off BA s/h in the first place.

On the lounge access side of things - it wouldn't surprise me to see them go down the AA route of locking out people on 'domestics' (or in our case - short haul). The fundamental problem they have there is that the people who fly enough to cause sufficient cost on that will simply credit to another OW programme and get access through the OW rules.