The amount of awful players who have no idea how to play this role in the immortal bracket is quite frankly nothing short of astounding. It's quite clear that most games the 4 or 5 on my team are just playing for the sake of getting role queue tokens and have no interest in the role. Sadly, position 5 and to a lesser degree, pos 4, are roles that have the potential to decide games within the first 10 mins and even beyond that, just by knowing what to do on their role. I think supports actually have more impact than carries in games. That's how important the role is, and people treat it as a dog role and end up griefing the game from start to end, because they ruin the safelane or offlane and then proceed to have no concept of counterwarding, or smoking. Too many games I have to watch these players on my team with 10 sentries and 3 smokes in stock and the game feels like a low skilled unranked game.
We all know that bad core players are prevalent as well and can greif games to an inevitable loss, but what I'm bringing to attention is in the current iteration of dota, bad supports players grief the game to the same degree or even more as the role has become one of the highest impact roles in the game.
Tldr: bad support players make this game a coin toss from the laning phase.