The condition of any public washroom largely depends upon where it is located.
The women's rooms in two supermarkets that are used like Grand Central Station, both in less prosperous sections of town, tend to be pretty grody and smell awful. Blocked toilets, some sort of fluid on the seats that might not be water, hand towels all over the floor, ewwwwwww all the way.
I see many possible reasons for such a mess, like moms taking little boys to the potty and the kids piss and miss; the toilet is already a mess and someone has assumed the "Toronto Airport Position," squatting above the bowl to avoid the unknown stuff on the seat and splashing or spraying the seat; and just plain "It's not my bathroom" as a reason to leave a mess.
Wal Mart, K Mart, supermarkets, and many gas bars have the worst potties around. Among the best are medium to upscale restaurants, auto dealerships, and government buildings accessible by the public, like a courts building.
Men's rooms aren't really in my bailiwick.
Wing Walker