Public toilets as we know them usually looks like this, .......scary and disgusting.
I totally get that anything public is a target of vandalism and destruction, but the better it looks from the beginning, the better ( any normal people ) will take care it. And that´s a fact !
The public toilet in Narita Airport, Japan has won Japans Transport Ministry Price as public toilet of the year. Which clearly was deserved. I don´t expect all public toilets to look like this, but you can do a lot for a lot less, and make a great difference in the way people will behave in these places. The right light, color and materials makes us behave with more respect towards things. Imagine yourself using these toilets in Narita airport, and coming out of there with no feeling of fear of diseases or disgust.