It was a big deal then, but over the ensuing years it becomes less of an issue. We are still concerned about having privacy as we use the bathroom, but we are not as concerned - nor should we be - with keeping it secure. The closed or mostly closed door is a signal to others in the household that we (or anyone else if not us because this applies universally) are in the bathroom and that we (or others, if that's the case) want them to remain outside.
They are just too many things that can happen inside a locked bathroom as we age that will slow a response from others in the home. In some cases a very quick response will be needed to prevent additional injury or summon medical help.
If someone is having cognitive issues where they become confused about their surroundings, could be startled by a shadow or something they perceive as unfamiliar or threatening to them, become disoriented and panic, or lose their balance and fall, they need immediate assistance. They may not understand or be able to help with unlocking the door from the inside, and it may be difficult to unlock from the outside also. This is where a locked door can become a major concern.
Bathrooms are notorious places for falls, and they can happen to anyone - not just seniors or those with cognitive concerns. So it really is a matter of family safety to be able to get into the bathroom in an emergency to provide assistance - without needing to unlock a door first.
Privacy and dignity can still be maintained without the necessity of having a locked door. Visitors to our homes can still lock the door to the powder room if they like, but this more a matter of the full bathrooms in other parts of the home that family members or visiting relatives might use. Of course, this discussion about us and our families, by extension, applies to the clients we serve. They face the same types of issues so we need to be prepared to explain to them why it's more of a privacy issue than security that need to consider.
With this change in emphasis - a paradigm shift, if you like - pocket doors become much more practical for use to use and recommend for our clients. Unlike a hinged door that either opens into the bathroom space and potentially interferes with or infringes upon the usable floor space in the bathroom, or it opens into the hallway or bedroom and can possibly block or restrict traffic flow in front of it. A sliding door such as a barn door would be a good choice as well.
With the way a bathroom door closes and latches - and locks - being less of an issue than just having it close, we have enhanced safety in our homes and those of our clients and broadened the door choices available to us.