There are a few reasons esperanto makes sense.

1. It's easy to learn.
2. The hypotetical: If you were a prisoner of war at a POW camp and you had to learn a language quickly so everyone could plan an escape or communicate in a way that the guards would have more difficulty understanding...esperanto makes sense.
3. English is difficult to learn. Non-English speakers the world over could more easily learn esperanto as a 'bridge' to english.
4. I will have to do some international travelling in the next few years and I have a better chance at finding people who speak Esperanto than I do at learning all the languages that I will encounter.
5. (probably the profound one but also the gamble) With the advent of the internet, people from many different cultures could use a 'made up language' (psst, they are all made up)to communicate...especially when there are a number of good FREE programs available to learn it.
6. Time: I've only been studying EO for a few weeks and I can interpret written EO very well and can understand at least the 'gist' of what is going on in the EO chat rooms.
7. Something in common: It's a cool way to meet interesting people, kinda like an IQ society but based on something more tangible...and useful (no offense to the HIQ deals).

I'm sure there are more and many drawbacks but the is my Humble Opinion.

Roberto Reynolds