What's up with this "get carried" Bronze V attitude?

It seems like everytime someone has a decent game or gets a really, really lucky roll on teamcomps, they like to attribute their victory to "skill". I recently played against an extremely toxic Tryndamere who literally said nothing but "get outplayed" the whole game and flame everyone because we couldn't kill him. I'm like, "Uh... do you even understand how your champion works?"

Are there seriously people who play this game who are either too stupid, too stuck up their own asses or a combination of the two to not realize the difference between skill and a champion's inherent kit? Flashing an important skillshot in the middle of a duel is skill. Baiting out abilities and juking stuns is skill. Pressing R because our Fiora just dashed to you and destroyed you for 3/4 of your health with 1 auto attack and then right clicking until she's dead is not skill. That's just how your champion works. You're not good, you just got lucky that the Fiora was stupid enough to engage you with your ulti up.

I see this so much with champions like Teemo too. Champions that have zero outplay potential, but with cheesy win mechanics that the players attribute to them simply being more skilled. I don't get it.

Normally, I would make a parallel to CoD and the "noob tube", but that's not even in the same category. At least the noob tube would require you to aim at your target first. Tons of people play champions with auto-win conditions like Teemo's Q or Tryndamere's R and think with the Bronze V mentality that just because they killed you in a situation where you simply couldn't fight back, that they somehow outplayed you.

What's the source of this kind of toxic behavior and is there any way to get people to see that they're just being egotistical and stupid?