This is probably a question better left for lawyers, but aren't there any rules in regards to the Alliance? If LH doesn't want to redeem awards from US or UA members, I'm sure then could try to convince the other members to evict them (2/3 majority might be enough). Or they could just leave the Alliance themselves. It seems like though either you 'are in or out', and until either of these actions happen, there should be no selective rules between member airlines. That really defeats a lot of the (so-called) advantages of being in an alliance.

Jeff