Why do low elo players thow around the word "ss" so much

For example i was playing Darius and I had a Shen support, i was playing against a Quinn, and she then just started to do the things that every Quinn should do ROAM, so she just went her merry way to bot, more then 3-4 times and because our Twitch had high ping he really wasnt able to do much but the Shen just went furious, he immediately pinged me saying "Darius ss?" I tried to explain to him that i couldnt do anything, that i had my tp on cooldown, but then he just said this "well why dont you just walk then" i almost bursted out laughing from that. I tried to explain to him YET AGAIN on why that is a bad idea but he just wouldnt listen, and right at the end he just said this to me "GG report Darius for not knowing how to fucking play the game" This game was honestly my worst experience in league and I am just gonna say that people need to know WHEN you can ss and HOW can you ss.

Thank you for hearing me out.