What you are assuming is possible is a logical contradiction. To be able to recognise two persons as being the same is in fact the definition of de-anonymisation. Please check your math.
Are you actually suggesting that SO/SE are blocking Tor because they intend to track all of their users by their IP addresses (or browser metadata), using national security as a justification?
I still do not understand how blocking Tor helps here. People who are concerned about their security will either use mirror sites, or use data dumps such as what is available at archive.org, or simply not use the SO/SE content at all. The number of users who will abandon Tor and the protection it provides for the express purpose of visiting SO/SE is negligible.
This move will not increase the number of persons who see SO/SE adverts or who are trackable by SO/SE. It will also not decrease the number of persons who will be able to access SO/SE content. So I continue to be mystified about the rationale behind this policy change.
Is this actually true? I've often used Tor to access Google Docs and Google Maps and to my knowledge have never had a problem. In fact, I'm not even presented with Captchas.
Actually, there is no evidence that Tor is any shadier than the rest of the Internet, especially given that most attacks and vandalism originate from botnets and other compromised systems, not Tor.
If by 'accountability' you mean the ability for site ops to unilaterally de-anonymise Tor users, then no; Tor users will never agree to that.
If SE executives are really concerned about spam and vandalism by anonymous actors, then SE could Tor users to post assets in escrow (e.g. Monero) before posting. Similarly, if SE executives are concerned about denial-of-service attacks, then SE could rate-limit the sites that are causing the attacks; Tor is not efficient for that kind of attack anyway. There is no sound argument that blocking Tor entirely would further the interests of SE users.
A site looking to grow its influence would be more concerned with attracting new users than repelling them. This is the act of a monopolist in secular decline.
If by 'accountability' you mean the ability for site ops to unilaterally de-anonymise Tor users, then no; Tor users will never agree to that.
If SE executives are really concerned about spam and vandalism by anonymous actors, then SE could Tor users to post assets in escrow (e.g. Monero) before posting. Similarly, if SE executives are concerned about denial-of-service attacks, then SE could rate-limit the sites that are causing the attacks; Tor is not efficient for that kind of attack anyway. There is no sound argument that blocking Tor entirely would further the interests of SE users.
This is the act of a monopolist in secular decline.