I think, not having read it entirely or recently. Perhaps the rationale is found in the Sharia, supposedly derived from 'principles' - thus subject to even more interpretation.. I pretend no more certainty about 'all the Muslims' than I believe there IS such a thing as, 'The Murican Peepul'. Imagine the actual diversity of individual practitioners (!) I can't.
As to emotion in conversion - even in supposedly intellectual pursuits, isn't the Aha! (when you get lucky) rather compelling evidence that a breakthrough is always accompanied by an emotional (pleasure / satisfaction)? That is: I don't believe it is possible to 'convert' (either way) from what is always a combination of mind/heart - without that which many call, an epiphany. (But of course - no one can ever know what another actually 'felt' except by deeming their report an honest one).
A.