Nobody moaned when LS moved in on Amsterdam, Paris, Newquay and now Bergerac. Seems what FR is doing is fair to me. Anyway, operators fall over themselves to fly routes out of Manchester, with two or more airlines often flying the same route, so I am sure that popular routes from Leeds can cope with two, and if LS do have to pull some thinner routes, then there are still plenty of unserved leisure destinations from Leeds to consider. NAP, FNC and a number of Greek islands spring straight to mind.
On a different note, has LEI gone?