They walk into a sandpit and think themselves lost in the Sahara. Whipping up dust storms by flittering from one vagueness to another. From one abstration to another and back again until this constant toing and froing is mistaken for something real.
This is why we have the word “bad.” …to distinguish between what is valuable and what is not. It doesn’t make sense to me to say that theorizing (forming theories?) is bad, or that philosophers as a rule deal in needless abstractions and helpless vagaries. It’s just that not everyone who aims to do philosophy, or who engages in theory, does a good job.