the way I meant it as a "it's not what they signed up for" was more like a:
each player signs up to a game under the conditions that there will be 1 player for each role and that each player will attempt to fulfill the general conditions that the role is specified for.
pretty vague right? I mean, you could twist all you want and somehow word-play that shit into like...saying AP Renekton Support being a legitimate, unreportable thing. And I'd agree with you, something like that would be completely ok (although it would still be hated for good reason) so long as you fullfill the requirements of your role
that does not include ignoring your roll as a support (aka being there for your lane partner adc in the bot lane) to fullfill the conditions of another role just because you want to. A support is a support, and if you sign up for a support you had better be supporting. If you wanted to jungle, sign up for jungle. If you wanted to double jungle, find a team of players that are alright with that because it is not a sanctioned strategy by Riot.
and if anyone tries to argue about roaming supports such as
, he still has lane presence and should be leaving lane to collect chimes at safe periods of time, not just abandoning your adc for the entire laning phase while stealing camps from his jungler and never helping the team beyond split pushing.