Having a bit of deja vu here. Exactly the same outrage several months ago when QF dropped the the same benefit. The effect there, along with other "enhancements" was a massive upswing in business for the domestic competition, DJ.
I've only been BA Gold for 2 months, so I will probably never get to use this benefit before it disappears on virtually no notice at all.
I agree with others that the outrage is inversely proportional to the degree of difference left between BA Silver and Gold. If you don't live near a First lounge, there is no incentive left for the extra 900 tier credits. Might as well give that revenue to another carrier, say one with a lifetime status benefit?
Some members have spoken of "unpublished" benefits of gold. Well, when you are travelling domestic H class and want to take an earlier flight, as a Gold Card Holder you can pay an extra GBP183 for GLA-LHR one way on top of what what you already paid, or wait 6 hours for the flight you originally booked - just like everyone else. No unpublished benefit there. No benefit at all, actually.