The specific reason for EI leaving OW is that JL joined and EI was required to spend millions of Euros to update its computer systems in order to be compatible with JL. EI expected about 10 pax/day extra due to JL joining, so basically EI would never recoup this investment or have any benefit from it. The LCC issue was decided several years earlier, when EI was allowed to remain in OW, so it was not the reason for leaving. After leaving OW, EI expects to have over 90% of their benefit from being part of OW by having bilateral agreements with AA and BA; so for EI it was an easy decision. Too bad that JL has computer systems that are so different from other airlines (this of course was one reason why JL did not want to join any alliance, and kept out for years).