The MCH seems like the 2.0 SMN, many people were talking bad about it and with parsers at hand. SMNs were left out and all DEVs did was nerf it by removing thunder as a crossclass DoT. After few months people understood finally how it worked and it found its well deserved place in the party.

Read your skills tooltip, experiment, share and take with other MCHs in a dedicated thread you can open in the DPS thread and things. Learn how to push your damage/utility to the max and things will end up nicely.

If someone lock you out just for your job of choice try to explain them and if they don't listen well.. Do you really want to play with idiots? Just report them.