Except you can't prove their intention is to troll just because they decided to go AP Rammus or anything else.
Literally the "can be powerful" remark was said for the specific reason that it depends on the player. Vayne can be powerful, Kai'sa can be powerful, etc... If in a player who can utilize it, which isn't me because fuck me playing adc.
That is the beauty about AD though, everyone can scale with it. Friend played AD Blitz bot with me as Leona, the butt touch combo was effective. But oh boy, can't wait to hear how you react to my AD Heimerdinger game; which won btw and contributed to the team.
That might be you, but others prefer the designated Tank supports like Leona, and Alistar. It was silver elo, but eh. Remember, not everyone has the same taste as you.
We apparently aren't going to change the others mind on what defines a troll. I believe trolling is playing without the intention to win. The only time a build is too far out there is if there is 0 benefit from it (eg AP Zed).