The only way you can out-DPS SMN as ACN is if you don't use Fester and don't routinely buff your pet damage. I'm not sure why you wouldn't do those things, but there it is.

The hostility comes for the same reason as people get hostile when other people play badly. Except this is worse, because you are willingly nerfing your own DPS, the sole reason for your class, simply out of some personal preference.