Physics noob here, but I feel like part of the reason is somewhat unintuitively that quantum physics is so badly understood.

On a logical level, you’d expect more openness for alternative theories when you don’t understand a field. But in practice, a lack of understanding means that you can’t evaluate alternative theories. You can’t decide whether it makes sense in all the aspects where it would need to get things right. And if you’re not aware of this bias, then it’s easy to point to your bible and dismiss anything else.