Anyone exiting a crashed airliner carrying any item of clothing or hand baggage in their hands should be arrested and charged both with endangering the safety of the other passengers and disregarding the lawful instructions of the crew
The reasons why it's unwise to get hand-baggage from lockers are a) time, b) blocking the aisle, and c) damaging the slides.
However, other characteristics of passengers affect these considerations. Clothes can hamper a person's manoeverability. Burkas, saris, thobes and other long voluminous garments are pretty much designed to catch on things and get in the way when you're clambering over seats, etc. Full-face burkas also reduce the capacity to see where you're going.
Aisles are likely to be blocked by families with young children, trying to get the brood together and shepherd them to the exit. It's still not uncommon for families to find themselves split up and sitting in different bits of the plane, because there aren't enough seats left in a block.
Accessories such as heavily studded belts must be just as good as stiletto heels for ripping slides. Some of the more extreme facial piercings look like they could do an amount of damage.
So do we forbid all passengers to travel unless they're in trousers and sneakers and their hair tied back, with nothing metal sticking out, travelling without children or elderly relatives?
At what point do we just make people strip off and put on orange jumpsuits?
Note: I think it would be sensible for airlines to require passengers to prepare for landing by putting their coats on and having vital documents / medicines in the seat pocket in front of them. But then, most economy seats barely fit a slim person in a t-shirt, never mind a large person in a parka.