I would like to point out that learning a computer language usually takes between a week and a month, while learning a natural one takes about a decade. I agree that knowing a natural language broadens the mind to some extent, but spending so much time to get such little reward seems a bit wasteful.
Exactly, that's why engineered auxiliary languages have always seemed like such a great idea to me (like esperanto or Novial). But, none of the offerings ever appealed to a critical mass of people. And, if I understand the history correctly, not-invented-here syndrome caused most moderate successes to splinter when people decided they could come up with something better.
