They said not generally intelligent, which is a specific and important property of AGI, not AI. In the tic tac toe example, the AI is intelligent (can play tic tac toe), but this intelligence cannot be generalised to playing chess, appreciating art, whatever the general measures may be.
I won't speak to the purification aspect (though I suspect purification is quite trivial), but helium released into the atmosphere is wasted. Saying it's not destroyed is by the by, we aren't going to recover it from space as it rapidly escapes the atmosphere.
They said not generally intelligent, which is a specific and important property of AGI, not AI. In the tic tac toe example, the AI is intelligent (can play tic tac toe), but this intelligence cannot be generalised to playing chess, appreciating art, whatever the general measures may be.