I'm guessing that the *fare* for BRS-FRA-JNB was probably about the same as the *fare* for BRS-AMS-JNB. What's a growing problem for LH though is the size of their fuel surcharges (YQ), which are now apparently out of proportion with the market.
It's certainly been the killer for me on some bookings. I can span a couple of hundred quid difference, justifying it on my SEN/*G status perks, and the possibilities to uses miles to u/grade and so on. But when the difference is getting in the order of £300+ (largely out of YQ), I just can't credibly sign it off (particularly in the current environment). And C class travel is completely off-limits.
I sense something is up more generally, and the BRS suspension is only a symptom of that. There's been activity in Japan to get LH's YQs down, and now YQ for journeys originating in Japan is half that of those originating in Europe. If there's going to be a significant reduction in YQ, then great, but obviously that hits the cashflow, and probably doesn't make the BRS route look very good financially.
Sadly it leaves BRS disconnected from the largest airline alliance network (until CO join in November). SkyTeam are, IMHO, a straggly bunch of airlines around AF/KL. And of course, we've no OW since BA became London Heathrow Airlines.