Getting flamed for going Veigar support?

So i have found a match and i thought i would do some mid. But our locked in before me so i decided to go Veigar Support. As soon as i locked in he started typing stuff like ''wtf Veigar?'' ''What are you doing Veigar?''

And when we started the match Ekko tried to convince the other team to report me for trolling, even though that wasn't my intention.

After the match still reported me even though i was helping out our adc quite a lot. I ended up having 4/0/15 and Vayne had 12/2/3 at the end of the game. I even helped Ekko secure a few kills too, and also helped in team fights, but he still decided to report me for ''trolling''.

Why did he do this? Is Veigar actually not a reliable support or did this player think Veigar works nowhere except mid and thought i was trying to ruin their game on purpose?