Oh yeah Lisp is the only community with hostile individuals. Every sizeable community has such people and one must know to avoid them. It's hostile in itself to derive ideas about communities themselves from indiviudals' behaviour.
Lisp's hostile reputation dates back to when most language discussions happened on comp.lang.lisp on Usenet and the toxic environment created by Erik Naggum and his acolytes. It's a hard reputation to shake, apparently, seeing that it's a subject that still comes up decades later.
If it's in the project's official screenshots (under the heading "Get excited"), it's not unreasonable to assume that it's representative of the project community.