The valuation crashing back to reality after going private, and therefore being measured by its intrinsic worth rather than whatever the latest trader paid for a share of it, was an inevitable but meaningless consequence.
Twitter has become text book bad purchase, bad management, and worst "rebranding" in history.
It was meaningless to Musk for all of about a week, when he came off his ketamine binge and realized what a stupid offer he’d made. But it was a done deal by that point.
According to Reddit[0], it might not have been meaningless to employees with unvested RSUs. They lacked an acceleration clause, so instead of immediately becoming 100% vested at $54.20, the schedule remained intact with a cash payout instead of stock. If the cash payout was relative to current company value, then it was a massive hit.
[0]: https://www.reddit.com/r/Twitter/comments/yykn1e/if_you_work...