Take for example some of the worst - Vegan Cross-fitters. Now, while i see them as 'horrible' people, I also see them as misinformed. This does not stop me from eating bacon in front of them. There are a myriad of ways to avoid them and their ilk. Here's the rub - THEY probably think the same thing as me (ikr, man-bun cray-cray).
So while you and others here are correct in that there are ignorant and horrible people out there that post goatse and blue waffles, racism, etc... and yes, it may interrupt your viewing/reading/research, that doesn't mean they should be stripped of their expression any more than you are for looking up amino acids or small engine repair.
In my (admittedly low-tech experience) Generally, if you're looking for an answer or doing research or have a specific point to be online, you know what sites are legit, and which are not - and which ones allow anything-goes. That list ebbs and flows as you visit more or less often, just like you know what bars are too rowdy at night. you know because you went there, once. ONCE. <insert Johnny Dangerously line here>.