Quote from ZomarYou say that as if you're under the impression that SW3 and SE:L will gain profit. Practically nobody makes in-game purchases for apps - especially not single players ones - and SW3 is another free-to-play flash game. Everything that they have done and will ever do concerning stickwar/empires is done because they enjoy(ed) doing it, and the small revenue from memberships is just a nice bonus. They're no longer focusing on it because they no longer enjoy it, and are therefore finding substitute projects. That's the most logical explanation anyway.
SW:L will pay for itself in video adds for a long time. That said I think you're generally right, SW1-3 almost certainly had/have no hope of paying for themselves and thus we shouldn't see money as the sole decision for the devs.