demotivationalist 

Someone who tries to demotivate or demoralize those advocating for social or political change, often by accusing them of being 'undercover feds' or that it's 'already too late'. This tactic is frequently used by activists to keep their opposition quiet.

After our political group was infiltrated by demotivationalists, no one wanted to organize be involved with it anymore.

demotivationalist by the big meme July 9, 2020

demotivationalizer 

An asswipe from any corporate headquarters obstensibly sent in to raise the bottom line, but is actually an un-fireable loser being transfered (and promoted) just to get rid of him/her.

This demotivationalizer they sent in from back east is the biggest demotivationilizer in the history of business enterprise. They musy have dumped him/her on us to get him out of their way without pissing off his/her daddy.

demotivationalizer by sali faloud October 10, 2005