Blame them all you want... That doesn't change the fact that all of your beloved 'local dive shops' are going out of business because they failed to target millennials and grow their business.
There's a huge market of millennials that are basically ignored by a good portion of the dive industry. You're not going to make your money by selling this group $3K of dive equipment. That comes later....
Dive companies need to use different platforms to reach this group. Figure out how to get them certified because they're not going to just randomly come to you, then make the dive process convenient. Delivery gear (partner with Uber or something), beach rentals, and dive charters where they show up and dive. 10 minutes of market research would show that this is would be more effective at banking off this group. Instead, the LDSs have the save business strategy as they did 25 years ago, and as those dives are getting out of the hobby, they have found themselves under hot water (little dive joke there).
Millenials make plenty of money these days, but they choose to spend it on experiences rather than thousands of $ of dive equipment. Plus, once this group does buy equipment, Amazon will beat the LDS time after time. The dive shops that are doing well boast their training programs and rental services.
Make the struggling shops should take notes grow with the market, instead of complaining that things aren't the way they used to be.