Perception

Sir, with all due respect, Everything you wrote and the questions you asked are fundamentally flawed, in my opinion.
It almost reads as if we all work for the same company but in different departments. You, as the CTO, stepped in to clear up some miscommunication between the devs on your engineering team and all of us in content management, and we should "work with you to ensure that the future of Stack Overflow is one we can all be proud of."
To help smooth things out, you also asked our team for feedback because, after all, our shared goal is "to make Stack Overflow the best it can be for everyone who uses it."

Translation: SO pays the bills, which should incentivize all of us to work smarter, not harder, and communicate more so both teams can focus on what really matters: the customers. Because if they aren't happy, the company loses money, which triggers budget cuts. And we all really need this job.

Reality

The reality is we do not work for Stack Overflow, nor are we your coworkers, which explains the overwhelming negative sentiment from the so-called and much-maligned "Community."
Now, a handful of us, either out of the kindness of our hearts or because it gives them a sense of purpose, choose to volunteer in our free time to maintain and safeguard this collective knowledge we have amassed. But we all have our own teams to lead, our own code to debug, our own features to ship, and our own paychecks to earn. We also have our own problems to solve, so we visit Stack Overflow to ask questions and search for answers. We are your customers.

I also want to piggyback off an observation Tyler brought up earlier today in his stellar response about how Stack Overflow employees rarely use their own product as a point of reference, much less bother to contribute anything. Why should they? The same could be said of their CTO...

Responses

"This (significant decline in user activity) is something we cannot ignore, and it's a key driver behind the changes we're making."

Actually, I can ignore it indefinitely; this doesn't pay my bills.

"We have to move away from a world where closing questions is essentially the catchall and default option for curation."

Actually, I can find answers elsewhere; I don't have to do anything.

"I want to understand what's most important to you, what you feel makes the site unusable, and how we can improve the tools you rely on."

Me: The UX of the site is most important to me. I, along with many others (feedback here), feel the proposed UX is abysmal and makes the site unusable by design. It should goes without saying that any discussion about improving tools while these fundamental concerns go unaddressed is simply a waste of time.

"With that in mind, our intent is to focus on tools that meet today's needs while taking a hard, analytical look at existing tools to see if they're still the right fit. While we may not have gotten it exactly right, I can assure you a lot of thought went into this redesign and direction."

Sir, with all due respect, In my opinion, considering you have zero firsthand experience on Stack Overflow, you are both ill-equipped and unqualified to meet today's needs. After all, to analyze the worth of a tool, you must both study its functions and learn to operate it with some degree of proficiency. And lastly, I can likewise assure you a lot of thought went into the redesign and direction of Windows 8. As they say, the road to hell is paved with good intentions.

Conclusion

I am not implying you are incompetent in any way, nor do I have anything against you personally. A lack of experience is simply a disadvantage, not a trait. From what I can tell, you seem honest, intelligent, direct and well-intentioned. It is just that, to quote you once more, I feel a good bit of frustration and skepticism.

The ball is in your court now, Sir.