It’s not necessarily true. I’ve always been into UX and UI, and quite often I’m choosing products based on their UI. I’ve always hated that people don’t easily accept UI changes, however I’ve never been among them. In fact, what made me interested in software engineering when I was 8 years old was software products with different then UIs than what was common at the time. This still hasn’t changed. iOS 7 was my favourite iOS release, as well as macOS Yosemite and Big Sur, cuz of their UI refreshes. However, there is a big difference between getting used to a UI change and a bad UX, which the new Safari in my opinion is. It got better with Beta 6, thankfully, Apple is listening to all the feedback. As we’ve seen in the past, Apple doesn’t usually change stuff they think it’s okay just based on user feedback. As they did now, it is another indication it was a wrong decision and someone in the team has eventually realised it.
Even if better in Beta 6, I still think Safari 15 is worse in iPadOS and Monterey (I don’t like the outlined address bar, the style of the tabs, among some bugs) than Safari 14. Btw, the Safari update was the only thing that got me excited from the WWDC21 announcements. However, after using it, it quickly turned into a disappointment.