God forbid an engineer should have an opinion on UI/UX.
I have long believed that the biggest issue here is that engineers and power users generally have a much higher “pain threshold” when it comes to poor or complex UI/UX. They are not always the best people to judge how or if less experienced users will tolerate or adapt to those patterns. It’s fine to have opinions but they must be prepared for them to be challenged. Even better if they can invite others to challenge them, which is essentially what talking to your users achieves.