basically echoing what is above, poor business practices are #1 that I say, failure to evolve is #2.
Poor business practices are really what kills me with a lot of them and you see it in Cave Country, coast of NC, and various local shops. Pitching "us vs. them" does not work, and it was really bad in Raleigh when I lived there and there were I think 6 active dive shops at the time in that city, with 1, yes 1, diving location within 50 miles.
One was ancient and I think it was just on cruise control since the owners were retirement aged and had already gotten their nut but that shop was depressing to go into.... one is Gypsy/Airtech which is the best of the lot especially with their pool, one was a tech diving shop that went under when the owner died, another is a tech diving shop that used to be active on this board but has alienated a lot of people in the last year, another just burned down but will be rebuilding and they had a dual business with boats and what not, and another one is just there.
Raleigh is a big city, with TONS of money but it's not that big, and it's not like it's a diving mecca with people coming in and out. The most stable shop stays stable because it owns AirTech which is probably the largest scuba repair shop in the country with I think 8 full-time repair techs *full time, with benefits, do nothing but repair scuba gear*, and it also has a heated pool that stays slammed with swimming lessons year-round. Dive shop is part of that and is doing very well, but the owner has said it alone wouldn't be able to keep that shop open so they have put more emphasis on the pool for swimming lessons *pretty much every kid takes swimming lessons and there is a non-stop turnover with kids*, and they have also started doing a lot of service for other dive shops who send their regs to them for repair. They have adapted, they have good business practices, and they are doing as well as they really can be given state of the industry as a whole.
In Greenville where I am now, there is 1 dive shop, in a much smaller city, but with a LOT of disposable income. Owner is a tech instructor through TDI, but does mostly recreational courses with new divers in the area. He seems to have a good group of local divers that come back and his shop is pretty small, but does well and is stable. If he had big competition come in from someone committed in the area, I think he'd be in trouble with the younger crowd.
The failure to evolve is an industry thing. People don't pay MSRP in brick and mortar stores anymore, they just don't. Dive Shops trying to sell gear at MSRP, and then the customer having to pay tax on top of that just isn't going to work. If you can't/won't meet the price of what someone else is selling the same product for, I have to have real good motivation to buy from you, ESPECIALLY if I have to pay sales tax on top of that. Now that can come from various other free stuff, fills/discounted training etc. It can also come from me really not liking another shop where I will go out of my way to avoid certain shops even if they have the cheapest price because I don't want to support one of them.
The industry and the shop owners have to realize that they have to compete with the likes of LeisurePro, Dive Gear Express, etc. Many of them were on the front end of it and are doing well, Northeast Scuba Supply, Dive Right in Scuba, Scubatoys, Cave Adventurers, etc. They have an online presence, they price-match to get your business, they will talk to you and give you proper advice etc. That's worth a lot.
Now, my thing. I understand that I am an outlier, I understand that I am not a profitable customer for an LDS because I have my own fill station *ironically stemmed from my lack of faith in most dive shops*, buy most of my gear used and what I don't buy used I get direct from the manufacturers, etc. What I can do though is help direct other divers to dive shops and those divers are profitable for them. I really think that the UK has it figured out though with the "club" mentality and I think if a lot of dive shops started moving towards creating that type of environment combined with best-practices for running a business, then they'd get a lot more traffic