Glock is a mature product. You can only do so much with it. Reduce costs to increase margin. Make small improvements to justify raising the price, market like mad to convice people that it is worth buying.
Their competitors are free to copy the best features and optimize their products and processes based on Glock's strengths and weaknesses and how the market sees them. Some people wanted Glock to add a manual safety. Boom, who makes polymer handguns with manual safeties now? Some people complained Glocks are bulky and feel funny in their hand. SR9 anyone, MP9?
I went with the Glock, but I'm very into brand loyalty, unless you piss me off I do business with what has worked for me in the past. I like the simpicity, I like the availability of parts, the service reputation and the fact that my last Glock was a great gun.
Decent law abiding people must fear criminals and the law while criminals have nothing to fear.