> Why?
It doesn't take a financial wizard to realize that Twitter was insolvent from the day it was purchased. Saddling a company with an interest payment that's nearly double revenue is a clear indication to me that the time period from purchase-to-bankruptcy was going to be measured in months. So we can be pretty confident that everyone involved with this purchase was expecting Twitter to die quickly.
You and I are on the same page. But the "why" is not "why would they make such a poor financial choice," since it's clear the answer to that is "to kill Twitter." The why is really, "why bother killing Twitter?" I get Musk's reasoning, but I don't understand what his co-investors get out of the deal. Authoritarian regimes benefit from having dissidents operate on a centralized platform, because it's easier to monitor. Killing twitter pushes these groups out to platforms that are going to be decentralized and impossible to block. It's weakening their grip, not reinforcing it.
My best guess is that they assumed that Musk would stay on post bankruptcy and act as their pro-authoritarian sock puppet. But they didn't anticipate his complete ineptitude would drive users off the platform in such numbers.