Yep. I just watched a video that talked about not blaming teammates, and I made the comment that, yeah, flaming teammates doesn't help, but sometimes it really is them losing the game for you cause only some champions can 1v5.
I just had a game as Brand support where my team decided that all AD was an acceptable decision (hence Brand support instead of Nami or something else). The enemy Blitzcrank was basically worthless in lane cause I just kept poking them down so much that engaging on us was a death wish. We start grouping and the enemy Veigar could basically one shot anyone on our team with his QR except our Sejuani jungle. The only teamfights we won were the ones where I basically full combo'd the Veigar and someone finished him off. If the support is the one who needs to eliminate the main targets, there's a problem. Granted, Brand is strong regardless of items, but still, I seemed to be the only one who tried to focus him out before the fights began. The enemy team even made the comment of something like "Brand v world" and "Brand tried to carry" in the end game chat.
That or another game I had, again as Brand support, where my Vayne just tunneled so hard all game. I would get a EQW combo off and get the enemy support down to 100 health and Vayne would run straight through the minion wave, tanking the enemy ADC and such trying to get that kill only to die without getting it. The enemy jungler showed for a few seconds and escaped my stun with something like 300 health. Then I watch Vayne leave lane and chase into the enemy jungle, running past their red buff and towards their base looking for the jungler only to get collapsed on by mid and support. Luckily the rest of our team was doing good so we won, but it took me dying to her tunnel vision twice before I just left her alone to farm at our tier 2 tower and went to help the rest of the team.