You are free to use it and verify with your own eyes what is written in the code base. Anyone can share their feedback with the developers if they want to, regardless if the code is open-source or not.
It should also be viewed through the eyes of non-technical users, who cannot do any verification themselves, but accept verification through any means. There are more and more people who look at the hardware wallet as just another device, refrigerator, TV, router... I would not ignore the number of those who will buy HW in a random shop, sometimes only on the basis of physical appearance.