For me it is valuable because I have seen the full arc of announcement, the physical models which were displayed, the creative ideas and people behind them, all the way to final completion. It is satisfying. It also gives me a clearer sense of what Disney was shooting for than if I just read a blog or watched a video.
Competition never hurts. I think the reality is bit more complex. Disney lost its way under Michael Eisner from about 1995-2006. Bob Iger has done a phenomenal job rebuilding the company and using great foresight to acquire Pixar and Lucasfilm. Marvel? For the movies, yes. For the parks? I hope they build an entire park dedicated to Marvel so I can avoid it. But it sounds like DCA is destined to have Marvel in it - a very good fit for the California theme... NOT.
Even worse at Disneyland - last new e-ticket was Indy. But they have done a great job moving the park forward while they built and then re-built DCA. Finally DL is getting a new E-ticket with SWL.
Does not seem that way to me. But again we view things differently.
It would probably be better for Disney if Avatar 2 came it 2019 than 2020, but once it does, then the whole Pandora cycle we are seeing now will start again. Plus with FOP they have in principle a re-programmable ride. So it can be changed whenever Disney decides to change it. Like Star Tours.