@RivetJoint: I don't think it's really flying 2 hours in the wrong direction. If I went to Heathrow, then I'd be taking the train nearly 2.5 hours in the wrong direction, and it would cost more.
LH are the only *A airline that offers a decent Premium Economy product to the US, so I would have ended up flying LHR-FRA/MUC even if I had gone to Heathrow.
@Rumor_Jay: The UK is treated as a sterile origination point (as is the US), so it is possible to land UK originating passengers straight to the sterile non-Schengen departures area. This happens at MUC (which is brilliantly configured for these things), but FRA is less well configured. BM flights *could* be landed into the B or Z departures area, but for some reason they aren't.