Actually I think the point was the change in policy by the dive shops of charging the same for nitrox or air. I guess some folks thought they were getting a "deal."
Yeah, I know... I just thought it was funny that we were having this thread about a $20 increase for a week of diving in a sport where people pay $1400 for a flashlight!
But looking at the larger issue, I don't really have a problem with unbundling costs. Like with airlines charging for luggage. One way of looking at it is that they are ripping you off by charging for something that you used to get for free. Another way of looking at it is why should people without luggage subsidize people who check bags. And of course, there is no "free" - no free shipping, no free breakfast, no free returns. There is the price that someone comes up with to cover both their costs and their profit. Money is fungible. If someone gives you something free, that means that they have just worked that cost into their prices.
Nitrox is sort of a special case - making it "free" makes people more likely to use it, which can reduce the injury rate if you look at a large enough experimental population. For one individual diver it may be irrelevant. But if people dive Nitrox because they figure that it's included, overall the very low DCS rate in the recreational diving population may drop even further.