Flash is, or at least used to be, the easy way out. People used it because it was easier than HTML5. Hence, when a company asks for a quote on an interactive site they often went for the Flash-version because it was cheaper (and not fully knowing the drawbacks).
Apple forced a change in the market. All of the sudden, these people who ordered the new project in Flash realized that they couldn't view the content on their shiny new toy.
You might argue the ability of using Flash as an option. I see the fact that both Apple (and now Google) have actively taken a stance against Flash as something good for the society as a whole. It's a step towards better, and more open standards.
This isn't to say that Flash is completely useless. Not too long ago, it wasn't even possible to do interactive things with HTML. At that point, Flash was the only option. Luckily, those days are over.