Thanks for all the constructive criticism. After considering all the arguments put forward in this thread, we've made the decision to disable the 2-way block feature. We have received a lot of feedback and concerns which highlight potential problems and abuse behind this function. While I still think it had a lot of potential, the way it was implemented allowed members to exclude others from entire threads and therefore hindered them to engage with the community and access information on a broad scale. That was never the intention behind this feature. It disrupted and limited access to conversations in a negative way and I do think this strongly outweights the benefits that were supposed to come with that function. I don't think a forum like ours that puts such a strong empathis on speech should rely on features that restricts it so heavily.
Tl;dr - this feature has been removed.