Honestly I agree with you on most of this, except for the whole part about MC being a dead game. I've heard that idea get tossed around a lot and I want to try and explain the other side of that story.
There are still a ton of Minecraft-focused communities and forums that all are plenty successful. Generally from what I've seen, people say that Minecraft is a dead game purely because they themselves lost interest in the game. Millions still play it, and I suspect that won't change anytime soon just due to the nature of the game. The game is, in a sense, virtual Lego - it can act as a survival tool but at the core a big focus is creativity. For the creatively-inclined, the game likely won't tire as easily - which is probably why I've been able to stick with it and love it for over 7 years now. As of lately, MC has actually been starting to trend upwards again. For some reason or another the game appears to be coming out of it's perceived dead state. My theory is that the issue is simply advertising. Nobody knows that we exist, and the few who do are people who came from old CU. Virtually everyone here is someone who was on ND or old CU at some point. The only exceptions being friends of those people from old CU. As such, those people have been moving on and nobody has come in to fill their place. I take full fault for that because I'm absolutely clueless on how to actually advertise without something to the effect of paying for premium server listing spots or something of that sort.
In regards to the idea of a total "reopening" and "clearing out all the old", I don't know if I'm quite keen on that idea. I'm very much in favor of historical preservation, and at the moment I'm not exactly all that comfortable with the idea of totally doing a 180 and effectively wiping away what we once had. I feel that we have a responsibility to honor the past - not just of the old CU, but of the small yet very real population of people who have stuck around in the new CU and ND too. I'm not entirely against having a focus on things that aren't Minecraft - the primary issue is that for the past several years I've been in a spot where I don't have a ton of resources to do things. That's about to change within the next month or so though.
Call it a block fetish (xd) or anything else, MC is something I'm passionate about and it's something that won't be going away anytime soon. I'm all ears for ideas for expansion, but it's likely going to be a long time before we see the end of CU's MC server. In regards to said expansion - what specifically are you suggesting? More servers? Ignoring servers and focusing on Forums/Discord? Something else entirely?