I draw the line at not having a private shower and toilet. Yeah, a lot of van dwellers utilize gyms for this, but I don't want to tie my basic hygiene to external sources.
I don't read parent as saying not to have a shower and toilet, I think they are just saying make the vehicle appear more utilitarian so as to not draw attention.
Port-a-potties and portable showers are a thing. They are cheap, lightweight and don't take much space. Not as good as gym showers but sufficient if you want the option not to rely on them.