M_V
Those FRA stats due tend to lend weight to the theory that dropping BRS-FRA was more political, and more about protecting LHR loads, than it was about the standalone performance of the route. I was led to believe that forward bookings on the route were also healthy.
(And your point about yields is also true. I can vouch that there was little availability of E, L, T fares on BRS-FRA, so everyone was paying good money).
Ironically, I think LH's tactic may have misfired, certainly in my experience.
My *A status is quite valuable to me (and Mrs. B_T at times). Flying ex-BRS meant every trip started BRS(LH)FRA-xxx, and because of fare combinations, the long-haul would nearly always be on LH too. (Exception - madness fares to SYD, probably driven by the SIN(SQ)SYD section).
But if I'm going to have to go to LHR, I'll chose any of the many *A carriers flying from there. So ironically, none of my flying ex-LHR has been on LH at all. I've flown SQ, LX (also ex-LCY), BD - but not LH, and not through FRA.
So by pulling BRS-FRA, it's meant I've spent no money with them at all since. Probably not quite the effect they were looking for.