But why should it be avoided?
I take my children in to the shower with me, I model how to wash yourself by washing myself, show them it's something we all do, not that they have to do just then.
At the swimming pool, we all go in to a family changing room together - I'm not going to leave my young kids outside so they don't see me naked- the risks aren't worth it.
I also think that teaching children what normal human bodies look like is a good thing - we don't all look like models, actors or even biological drawings.
It allows for natural conversations to occur (why I don't have a penis, why I have hair, why my bum is big, what stretch marks are). It also allows for conversations about privacy, who can see you naked, how you can choose not to be seen naked etc.
Also, when you have a toilet raining toddler and only one bathroom, it's a heck of a lot easier!