The problem with the culture of "just assume people are joking" is that some people aren't joking. The background of edgy jokes was used very effectively by actual hate movements, to massive impact.

We all have to live with the consequences of that, and one of yours is that you're not getting the benefit of the doubt on nasty jokes anymore.

You need to acknowledge that something went wrong, and then consider why it did. Rather than have this naive nostalgia for an internet culture that only existed because "thick-skinned" is a euphemism for "people not actually in danger."