Public restrooms and common courtesy

WTF people?!?
I work in a high traffic area.
In 2009, the tenth busiest airport in the world - over 50 million passengers traveled through Denver International Airport.
"DIA was voted Best Airport in North America by readers of Business Traveler Magazine five years in a row (2005–2009) and was named "America's Best Run Airport" by Time in 2002." (wikipedia)

I go to work with the knowledge that thousands and thousands of people are going to walk past me at some point during the course of the day.
Many of these people have to go to the bathroom. Makes sense. Passengers are told to arrive at the airport two hours prior to their departure. Sometimes there are delays. The airport is littered with restaurants and bars. It is inevitable that at some point or another, every single person will have to use the bathroom.
I am generally at the airport for a minimum of nine hours per day. Some days I tap out at eighteen hours. I probably use the restroom four to six times per day, at a minimum.
90% of the time I enter the bathroom stall, there is urine on the seat.
Every time I walk in, I know I will have to wipe the seat before I pull the wrapper (hanging silently, yet politely above the toilet) out and place it on the toilet seat. Do people not know what the paper wrap is for? Are people too lazy to pull one out and lay it atop the seat before they piss all over it? Do some people think their aim is so amazing, they do not need the toilet cover? Because whatever the reason - IT'S WRONG.
You people who don't have the courtesy to put a FREE toilet cover on the seat you sit on, or sit over, or squat atop - whatever the hell you are doing in there, are pissing off the rest of the population who has to clean up after you, or God forbid, accidentally sit in your piss drops.
And explain this to me - when you stand up and see the piss droplets on the seat, why don't you wipe them off? Are you so selfish and trifling that you think, "no one knows I splattered and I don't give a F*ck".
I know.
I go in the bathroom stall behind you and YOU SUCK!

And the only thought that gives me any satisfaction as I squat above the toilet on my break, (wishing I was home comfortably sitting on my clean seat), after smiling at you and wishing you the best (and safest) flight ever, is the knowledge that karma's a bitch. One day, while you are grimacing because you accidentally sat in someone else's piss; as you reach to find a scrap of toilet paper to wipe your wet cheek...and there's none there, you will possibly think to yourself, "This is my piss. I did this to someone else and the world has finally revolved in their favor".