I think a lot of people are taking this in a way it isn't meant to be, such as actually believing that some one will be banned for being an unskilled player. I seriously doubt Riot would ever ban someone simply for not being good at the game, the idea is ludicrous.
People seem to be worrying about getting reported for that one game where you do awful trying a new champ, don't be. This kind of thing, and any of the reports as I would imagine, would most likely not be taken into account unless the player had a very large number of similar reports across a lot of games. Getting reported as unskilled a few times doesn't mean anything in the grand scheme of things, but if you start to have unskilled reports on you through something like 1/3 of your total games, chances are you might not be the best player.
So don't get all worked up over something that you don't need to, a few reports (of any kind, I'm sure) here and there aren't going to have any effect, it's when a player has repeated reports of the same kind that action would be taken, and the "unskilled player" report I am certain is not something intended to use for bans but most likely something used to match such a player at a more appropriate level.
*Note that I don't actually have any information on how Riot uses this stuff, I'm just operating on what I believe to be common sense.