Even then, I vehemently disagree with you, but I at least can follow the logic.
Arguing that clozapine, diazepam, fluoxetine, etc., are gateway drugs for heroine is an argument I've never heard before. It sounds ridiculous to me, but if you have evidence to support the claim, please post.
But on your point, personally I think abuse of benzodiazepines is more likely to lead to a drug like Heroin than psychedelics are. The whole concept of "gateway drugs" hasn't been proven, but the effect of benzos is a lot closer to heroin than psychedelics (anyone who has actually tried heroin might correct me on this...), so would imagine a stronger cross-over (even if not due to a gateway effect, simply down to the fact that anyone who likes downers is likely to try other downers).
Yes, you are correct. My bad.