The reason why I personally despite them is the fact how badly they're programmed/balanced. They can be behind a cover very far away and shoot pixel perfect at your location without coming out while you try to deal with the horde being unable to kill them unless you're mobile enough. Not to mention that they will practically teleport (move absurdly fast from one location to another) from time to time making it harder to get a good aim on them.
E: and sure, that's not that big of a problem on lower hazards but when you play on haz 5 it quickly becomes a problem with their amount and the hordes blocking your way.
You confused the bugs. Spreader is the red bug shooting this red goo from a distance. But ye, the meme can as well apply to... stalkers? Don't remember how they were called as I haven't played the new season much.