I often have to defend my sidemount setup facing divers who dive with normal BCD and single bottle. It bothers me. Is there other who gets annoying comments from people who think it's ridiculous, and dont understand why you dont dive as the them and what do you say?
I have never had this experience. I have had a boat captain make sarcastic remarks about my SM rig, but there was a back-story that allowed me to understand the comment, and that it was not directed at me. Years ago, I slung a pony bottle on a shallow reef dive in FL (because it was a new gear item for me, I wanted to practice with it and tweak the rigging before diving the Spiegel Grove later in the week), and the boat captain was quite sarcastic - in front of others on the boat - about me 'needing a stage bottle on the reef'. I just ignore those kinds of comments, I avoid responding with hand gestures, and I never feel any need to defend my rig. I generally prefer the Rhett Butler approach ('Frankly, Scarlett . . .'). With SM, what I almost always get is genuine curiosity, and a chance to engage divers in discussion about something with which they are unfamiliar.
Personally, I am happy that dive shops are able to sell gear, at a profit. I am happy that manufacturers are able to sell gear, at a profit. That allows them to invest in the development of commercial gear for smaller markets. We have seen an explosion in commercially available SM rigs over the past 5 years - just take a look at DevonDiver's list of available rigs, on his website (
Sidemount Diving Articles and News)! I won't say that all of those rigs are 'good', but the fact is that when manufacturers believe there is a potential market, and choose to explore it, there is at least some likelihood that I/we will benefit from the availability of a product that wasn't there before.
I do object to the active dissemination of mis-information ('Sidemount is only for caves'; 'Backplates are only for technical diving'; etc.), irrespective of the source (shops, manufacturers, or individual divers). But, in most cases, I think that occurs because of ignorance, or fear, or desperation, more than greed. A shop owner, who has no experience with sidemount (or doubles diving of any kind for that matter), and who doesn't stock / sell SM rigs, is possibly more likely to tell a recreational diver customer who asks about SM, 'Sidemount is only for cave diving, what you want is . . .', out of fear of losing a possible sale. Call that greed if you want. I see it as ignorance, or a desperate attempt to make a sale, and stay in business.