So who on earth would be irresponsible enough to trust Twitter with anything essential or important after this? Who is going to build a storefront on a platform where they might wake up one day and find out that all of their customers are rate-limited from using the platform? And then the CEO jokes that he's doing people a favor by making them touch grass?
A bunch of artists who had (shortsightedly) built their business models around using Twitter as an art platform woke up one day to find out that their artwork can no longer be embedded in other websites. A bunch of government agencies and public services just found out that "check our Twitter for updates" no longer works. With no warning and with no announcement, all because Elon is mad that OpenAI hasn't cut him a check.
That is a business-destroying decision. Other executives are afraid of doing this because it's the kind of thing that permanently hinders your platform from ever being treated like a reliable place to do business or build on top of. It puts a mark on your businesses reputation that will never go away. And it's not a tech issue, it's a trust issue. Finish the big work and make something exciting, sure, but nobody with an ounce of sense would ever trust Elon not to pull the rug out from under them now.
You're going to build a business on a platform that might randomly decide to effectively shut itself down on a whim? Imagine if you had an Amazon shop and Amazon decided tomorrow with no warning that every customer on the platform is limited to buying at most one item per day, and also external links to Amazon no longer work for guest checkout unless your customer makes an account. How are people defending this? It makes no sense.