Mythic raiding is plenty alive, officers not willing to put in the effort to recruit or merge guilds with another recruiting guild? Sounds like your problem.Mythic raiding to stay alive absolutely needs to have the 10-man/20-man option to it. I know personally I am fully BiS Heroic geared on my Ele sham and can do the mythic content the problem is my guild broke up due to the lack of being able to recruit and even recruiting getting a consistent number of people to show on the given raid nights. There is nothing wrong with the difficulty of mythic I love it. But even after talking to many people about the idea of it either having a 10 man option or even being able to flex it but make it guild only or even cross-realm it (last resort type of option, would make it way too casual.)
But oh wait now people are gonna say that it would make it casual and that's not what its made for right? Well why not? The competitive scene will still be just that, competitive . My experience people just have a preference now of how many people they are comfortable with I personally am more comfortable with 9 others than 19 others. Where there are people you feel the opposite. Obviously this is just an idea, and its not perfect by any means. But there is a way to make it work.
I just personally enjoyed the old raiding system the competition was greater you had 25 man guilds doing their content heroic and what not and then 10 man guilds doing their heroic content and such, people raided with whatever they felt comfortable in some 10, some 25. People say the gear difference was an obligation to raid 25 blah blah but forget the competition was in 2 different brackets so the gear was fine. At the end of the day all it came down to was choice of said person wanting to raid you can either join a 10 man guild or 25 man. but now take that concept into just mythic raiding with the gear and such staying the same now all you have is the competition in 2 different brackets again. Which from the people I've talked to both Hardcore raiders 10/10 mythic and just heroic guilds. A lot of them would enjoy that more than the one set difficulty , 20 people or you can't do it.