Korean is a skyTeam member, not one world.
Shame to see flyBE can't make it work to FRA, but I suspect that LH dominates traffic the combination of massive hub connections allow multiple daily flights, which is attractive for the O@D passenger too. LH have quite the operation in MAN, with multiple daily flits to FRA, MUC, DUS, HAM of course LX to ZRH, GVA and BD to BSL and SN to BRU.