Unfortunately, many people abuse "ass-gaskets". They don't just use one, but several at a time which clogs up sewage pipes (plumbers are expensive). Some people even steal ass gaskets (who knows why). Since a box of 250 cost anywhere from $15-$20 (some places go through 5 boxes a day due to theft and overuse), many companies are choosing to budget that money elsewhere. The place where I used to work went through 15 to 25 cases of ass-gaskets a week! Corporate finally got fed up with it and put a moratorium on them. Also, recent studies have come out claiming that public toilets aren't any more sanitary using an ass-gasket than using one without one.
They are everywhere here in Florida. I don't know if it's law in some counties or what, but the times (few as they are) that I've been in public bathrooms they always have seat covers. I hate using public bathrooms so badly that I often go home when I need to go. Hey...........it's a small town. :)