The internet is a different place than it used to be. These days every third person you see might tell you the California fires are caused by having too many black folks in the movies and be completely sure of themselves that this is a fact. It is no longer safe to assume sarcasm when you see someone say something ridiculous.

And if you just laugh and agree with it (sarcastically) or ignore it, then you’re going to get new people seeing this for the first time, not getting that it’s sarcasm, seeing it get agreed with or at least not refuted, and now you have two people that believe this mess. Rinse and repeat. 4chan is basically a case study for this sort of thing.