There are no numbers here, so this is literally impossible to debate. You can say X, I can say Y, and it's all completely subjective.
I personally don't think that he's driving away people like people claim. RMS is involved with the gnu project, fsf, and free software (now renamed open source), but those projects are each far bigger than he is.
> What if he's not so brilliant after all and you're allowing one "genius" to cost you equivalent or even superior "geniuses" with less abrasive personalities?
Again, this is impossible to debate in good faith. There are infinite hypothetical alternate realities, what good does it do for any of us to muse over them? Maybe a "super genius" exists and is being held back by RMS' continued existence. Maybe not.