PSA: The support isn't going to have a stellar kda.

That soraka isn't gonna be 15/3/6, especially if you lose. You have to throw shade at the support wait till the end of the game and check out the vision stats. Support should outward the rest of the team, easy peasy. Also take note of how the adc was, and understand there's not a lot you can do if Ashe REAAAAALLY wants to tower dive and the support was running back from base.

Note: there's exceptions to everything. Support or not feeding ain't cool. Some supports are gonna get kills, and some supports are gonna be bad. Just take 5 seconds and think before you play the blame game.