>>12
Well, for one thing, it prevents the creation and widespread acceptance of a REAL interlang. Esperanto and interlangs are a good idea to get people a common easy to learn language, however the language of Esperanto is Eurocentric (quick find 15 words in Esperanto that aren't European in origin), and hopelessly complex. It would be best to start over at this point, yet because Esperanto is popular, no other language is going to overtake it in the near term.
I've found dozens of workable solutions, yet no one will really start on Toki Pona, Glossa, or Lojban because Esperanto is always there as the "default".