Questioning status quo in mental health

There are many things in nursing and health care that seem to happen because 'we have always done it that way'
Sometimes that's good-after all Florence Nightingale said that having a clean hospital would keep people healthier-it turns out that handwashing works.
Sometimes I don't know the purpose of it. Why do psychiatric patients sometimes have to wear pyjamas? After all the nurses are wearing street clothes-why don't the patients?
Not all psychiatric patients do, but some have to, and I actually don't know the reason why.
I suppose it is because of the risk of people running off-part of some illnesses includes lack of insight-meaning people don't realize that they have a mental illness-so people would rather not be in hospital because they don't see the need for it. Another part would be safety-having people in pyjamas gives an opportunity to examine clothes and make sure there is nothing harmful in pockets etc. And I would think another advantage would be that if someone has been neglecting their hygiene due to another sign of illness-lack of self care-clean pyjamas is an improvement.
So, there are some good reasons for it. But there are also some problems with it. Wearing pyjamas singles you out as a psych patient-not just another patient in the hospital-but the only patients who wear the pj's.
Another issue is that it is not good to wear pj's all day. 'Normal' people don't do that-and a sign of getting better when you are sick is wearing clothes.
A large issue is that people feel embarrassed wearing them-no underwear, just pj's, for women this is quite embarrassing-no bra, especially when you consider that substantial numbers of women in in patient settings have had violence -up to 70% have experienced physical and sexual abuse. Having to wear clothes that leave people feeling vulnerable and exposed could create harm.
Which is the better way?
I need to do research on this...