@DANDAN_THE_DANDAN Based on the responses Id say you successfully created a better argument for debate.
Now about the debate...
I've always considered shoujou ai and shounen ai to be to ecchi what yuri and yaoi are to hentai. That is, perverted material versus explicit pornography. The few definitions of each term available online seem to agree with me. Still I've seen titles that stray outside the AI labels and into H territory and vice versa.
I'm looking for a reason to oppose you on this one but I cant find it. I believe genres need to be distinct to be useful so its best to not use these labels interchangeably. This is especially true in the case of an ecchi label being used where hentai is needed.
Come to think of it there was a discussion about a classification between all ages and hentai needed at MD. Time to see how that turned out.