How bold, to speak for everyone ;-)
I really don't see this as a "treat employees nicely" issue. I'm open to being convinced otherwise. But... Elon's premise from day 0 was that Twitter was mismanaged -- bloated, misguided, bad as a business and broken as product. This echoes the sentiment even by many here on HN over the years. Now Elon owns it, and is undoing the hiring decisions of previous management, to start with a clean slate. Seems to me this was simply an inexorable part of his takeover, and so you may as well be saying it "wasn't nice" of Elon to buy the company.
Also, a completely different counterpoint: If an employee's layoff is inevitable, it is much nicer for that is be part of a mass layoff like this, rather than a surgical one later. Because these people have a perfect explanation for their dismissal when they apply at their next job.