It's possible they kicked you for "play style" reasons. You might've been pulling abysmal numbers and didn't mesh with their play style (aka caring about their rotations and speed of run). While it hurts my brain thinking that some people care about a level 50s rotation, there are people out there like that. It's been confirmed/said by the devs that a clash in play style is a legitimate reason to kick someone from a party, so if that was the reason you might not find justice. This also applies to someone who likes fast runs and gets pissy at people who don't. The party can kick that pissy person because their play styles don't mesh.