Lack of new content and no maintenance make MMOs go dodo. Not microtransactions.
I've heard about ppl wanting new content and games dying because they keep refreshing all over the same thing, but i dont think games really need new content so often. In my opinion they need good scalability from the start, a good base, and to have a not extremely greedy company behind it. Wow proved it in the past. Wondering why the **** nobody copies them.