What is Deletist?
1.
A person (most commonly an administrator of a site) who likes to delete other people's posts. It's not always warranted deletions, but sometimes they're deleted because they don't follow some set of lame guidelines that has no relevance to the real world, but always gives the deletist a reason to erase facts and interesting comments for his own pleasure. These people are most frequently found on sites like wikipedia.
"That annoying deletist has yet again deleted my repeated attempts to add information for wikifascism on wikipedia!"
See
2.
Someone who habitually deletes anything they can, automatically.
"Hey, did you get me last email"?
"Nah dude, it went right into the trash folder. Don't you know I am a deletist?".
See