sure I have, and I've probably played this game longer than you.
Around 2 yrs ago, Riot changed the reporting categories. Back in the days there was a reporting option "unskilled player" . It allows the system to slightly adjust the MMR of the reported player against the one reporting and that was it. It was also a venting tool for the ones in rage.
Keep in mind, no one ever got banned / punished with the "unskilled player" option, but since many people don't come on the boards to read, they thought it will do something against the bad players. When in truth, it doesn't.
After the categories changed, people's behavior / habbit hasn't changed, so they keep up the same attitude "if you are bad, I'm going to report you" . Also, people now say "if I loose I'll report you".
Now, they can report for anything, but understand the system validates those reports. So false reports get thrown out, and it'll lower the report weight of the ones sending out false reports.
I am comfortable with people reporting me, cos I know it doesn't do anything to me. Since I didn't do anything against the TOS.
If people were mature, it's not hard to shrug off pixelated insults that don't do anything (other than attempts to hurt your e-pen).