I know I'm like two weeks late here but I like [url=https://www.youtube.com/watch?v=JweTAhyR4o0]this video[/url] in regards to this question. The tone can offend a lot of people, but keep in mind casual doesn't necessarily mean bad. But I think it's a reason why we see a decline in gaming, especially in the case of games being made for consoles before PCs. 

However, I'd still argue that games have overall improved and continue to do so. It's just easier to make bad ones and the whole market is a cash cow.