"Tanks and cc win games" he said

So i had a Tristana in the bot lane. When we were in lobby and i hovered over Master Yi, Tristana instantly typed "Another bad Yi?" Why do people have to assume people playing "braindead" champions are bad. When we got in game it was all normal then this happens. Enemy Double kill! Our Tristana says that "Tanks and CC win games". Technically that's correct but there are way more team comps that can win games besides Tanks and CC. Our Tristana starts Flaming our brand. WHICH DOES BETTER THAN HIM AFTER THE GAME Tristana 0/8/3 Brand 3/7/8 TBH I don't know if this guy doesn't know that since he's ad carry. Why is he playing an AD carry but not a tank since he did previously say that "Tank and CC win games" We lost because of him. Tristana on the other hand blames our brand and Me for not picking a "good" jungler or "good" support like a tank with good cc. I reported him after but he didn't get that suspension :(