Sorry to be the dim tart here - but surely it's only worthwhile to do this if you are actually going to be using the airline? i'm sure that it will get you into loads of lounges - LH I do understand - but Turkish? They fly to lots of places I know but is it always convenient to go via Istanbul? I read someone else was matched by AC - do you fly them?

I do get a sense that people try to get matches when they are flying Y with that airline on a particular trip and want to get into Lounges or maybe upgrade? I really cannot quite see the point unless you are going to change you flying habits or the company for whom you work changes its policies on which airlines are preferred.

I still do not see why a conversation should have started with the OP asking information about why such or such a policy exists. She did not make the policy and beyond saying that it is not BA policy I cannot see what further discussion achieves.