in certain regions it's not about the "meta" in solo que, but more about who can carry with x champ. you get a lane and then go where you want in order to earn gold and xp. if you have a lot of gold and xp and know how to play your champion you can carry regardless of team composition. at least that's the theory.
you'll see that a lot on the boards when people are complaining about the lack of teamwork or when people are constantly saying things like "get good" or whatever.
in the NA server though the majority of the community has an idealistic approach to the game and instead of being open minded about it they cram that idealistic approach down everyone else's throat and in the event where someone goes against the grain players tend to overreact and threaten mutiny.
partly this is because NA is full of players who have leisure time, money, and a large community of friends who enjoy similar interests. on other servers the game is played less like a team sport and more like a free for all.
"is it reportable"
the short answer is everything is reportable. the report function is no longer looked at as a way for players to finger out specific scenarios, but instead to address growing concerns. if you dont like something someone does then report them. it acts like a voting system and if enough people decide they don't like it that players account gets flagged for reformation.
would i report someone for playing caitlyn support and clearing parts of the jungle? no. why? simplest reason is because they're securing income and xp for their team and preventing it from the opponents. if i were the jinx in this scenario i would have focused my build towards defense instead of offense and hoped to hold out long enough for someone to get first tower on our team and if i didn't think i could i would ping for assistance until the turret fell and then retreat to another turret. it's that simple.