I did not answer the survey, but I might now that I see it is still open. I will make two separate posts to make two separate points, and I will make a summarizing post. This one will dwell on differences related to location.
I live in Colorado, USA. I am one of only a handful of tech instructors in the state, and that is because the local market is such that if there were only one of us handling all the potential students, we still would not make an independent living. This is true throughout the midwest. I recently had a potential student inquire about my availability. He lives in South Dakota. Many of the students I have taught do not live in Colorado, so I am very used to working with students living more than 6 hours away from me.
In Colorado, the deepest diving available (unless you go up to deep mountain lakes near timberline) is about 35 feet deep, with horrible visibility. Driving 6 hours puts me in the Blue Hole in New Mexico, with a maximum depth of 85 feet if you go down to what is essentially a pit. It is really only about 75 feet deep. The only site deep enough for tech diving training is a few miles away from the Blue Hole, and it offers 280 feet of depth. I think it's a great site, but it is on private property, the owner has no need for the income generated by the fees we pay, and the owner is concerned about potential liability issues. In the last few years, we have been told diving will no longer be allowed there several times, and if that ever actually happens, I will be out of business. There is no other site within a long day's drive that provides the depth needed for technical dives.
Because of those diving conditions, the market is predictably small. Because the market is predictably small, local dive shops will not support it. Their target market is divers who go on trips to remote dive resorts with them. Consequently, the only gear almost any of them have on hand for sale is typical recreational gear, with a focus on jacket-style BCDs. They all have access to tech gear through their suppliers, but they do not want unsold inventory, so any tech purchase will require a special order. The shop I worked for when I started teaching tech (next post) sold Oceanic gear, so they could order Hollis for tech gear. It took at least a month for Hollis to fill such an order, and students found they could have the same gear in a couple of days if they ordered it from an only shop. So the shop owner said, "See! Selling tech gear does us no good, because the students don't buy it from us."
Shops not supporting tech extends as well to breathing gases. I only know of one Colorado shop that offers trimix, and I don't know any in New Mexico, where we use it. That means I have to make my own. I have an account with a local supplier, and when I drive to New Mexico to dive, I take a van full of helium and oxygen supply bottles, and I bring a booster. Buying my own van and fill equipment was a big purchase, but that is the next post, too.