Insane Olicity 'fans' like to inflate their numbers. If you see Twitter, they have like hundreds of bots that get artificial trendings in order to pretend they aren't just an insane minority. But Twitter is a disgrace of a website that won't fix all of the fake accounts. If they won't stop actual terrorists from recruiting people on Twitter, then they certainly won't stop the Olicity stuff either considering that would be much lower on the priority list (if twitter actually had that list).

The fact that Oliciters have to cheat to seem like they matter means that they know deep down that they aren't as big a force as they like to say. If they were truly confident in the character's appeal, then they'd just let things go with the flow. But in actuality, they are likely insecure about it and so that manifests as doing things like harassing actors and their families. It's like religious fundamentalists; if they were so secure about their god, they wouldn't have to lash out so much. Somebody confident in their beliefs would just relax instead of trying to destroy those who represent other views who aren't going away so easily. It's basically how any crazy group works on any level - they are fueled by insecurity in the belief they are trying to defend.

tl;dr, Olicity fans are actually Hive.