>>There are people whose mother tongue is esperanto, you know. ; )
>sucks to be them.

I'll ignore your (non-)seriousness level and counter-argue for a bit. I think it would work quite well and be quite nice, actually. Esperanto isn't anything like a "crazy moon language" or anything. Rather, it appears to be a hybrid of latin/germanic/slavic languages, making anyone who speaks it a much better learner of many European languages than a random person.

Also, someone who has parents willing to teach them Esperanto as first language will very probably be in an environment that's very good for learning languages anyway.

There are probably thousands of "natural languages" with very few remaining speakers which it "sucks" way more to be born into - Wikipedia gives estimates of first/seconds language speakers as 1000/100 000, and those people will certainly stay in touch quite well.