The base of his argument is offending a persons preferences is not sufficient to self censor ones own actions - and I agree.
I also agree where he said any legal start up is fine and free of guilt - but don't worry I would be behind any start up or government initiative that gave away heroin to Junkies. The so called British System worked very well for many years, until the Puritan guilt pressure ended it in spite of empirical evidence that harm reduction did in fact reduce harm
so convert your start up to social entrpreneur status, and go make something to be proud of
the only reason to feel guilty is to have talent to create and not do so.