I have to agree with most of the others here. Sure, you can report someone for it, but the report probably will be discarded by the system. There was a reason that Riot removed the "unskilled player" reporting category. Many of these sorts of reports are based predominantly on opinion.
....And I disagree, I think that building this as the ADC, without asking the team first AND into a bad comp is not ok....
....then I think he should at least try to adapt...
.....you might think, but you would be wrong because...
I took those quotes from your posts. And what they all have in common is that they are your opinion. Is your logic sound? In this situation, it appears to be. Does that mean it will always be? No. Even the best players in the world make mistakes in judgment from time to time. And the lower in skill a player gets, the more likely they are to think they know what is best in a situation. Is it fair to to other players to subject them to the opinions of someone who, by nature of the limitations of their skill, has the potential to be incorrect?
At the end of the day, it's not really any player's job to nitpick at another player and tell them step by step what they should or should not be doing in a game; be it build, playstyle, etc. Sure, you can give advice, or friendly suggestions, but you cannot control what they do, and if they choose to ignore it, then you have no right to try and force them to, or to threaten them with punishment for it. They have the right to build as they would like to, within the bounds of not trolling (i.e. tears on riven).