My guesses:

• Intoxication: They're drunk or high enough that they're not neurologically capable of aiming; the fact that they managed to get it out of their pants at all is astonishing.
• Narcissism: They're very important assistant sales managers, talking on their phone through the whole transaction, and aren't paying attention to what they're peeing on; just as they don't remove their dirty dishes from the office meeting rooms after a lunch meeting. Aren't the help supposed to do that?
• Helplessness and/or disgust: The toilet was already filthy when they came in, and they didn't think they were making it any worse.
• Peevishness: They got yelled at by a scary janitor once for sticking gum under desks.

Related question, why the fuck do some people feel it necessary to grunt, moan, pant, and otherwise loudly vocalize while shitting? Zero people want to hear you, shut the fuck up, you are gross.

I've thought about this a lot over the years, I think it's just as simple as "all care, no responsibility" meaning if the average punter goes into a public toilet and somebody hasn't cleaned up after themselves (mistakes happen) then that dude sure as shit isn't going to clean up but he still needs to go therefore he'll do his best to be clean but if he has to do some sort of gymnastics to keep himself clean then so be it and if the toilet gets messier as a result of those gymnastics then so be it, the cycle continues.

I used to hate urinals and I still don't like them, but I understand the reason behind it, people are animals when it's not their property.

Also wash your hands afterwards! The pandemic should have highlighted the importance of basic hygiene.

Are we entirely sure no women are squatting and also creating this problem? Because I have witnessed exactly that phoenomenon occur in a bathroom before while attending the restroom with previous partners.

we stand and pee, sometimes it splatters

Can we not bring over these ranty non-questions from reddit please