heh, true! this is technically incorrect...but still pretty much necessary, for a number of reasons:
- most silo comments-on-comments are replies to other silo comments, not to your own POSSED comments. if we mirror that strictly correctly, there won't be a link to your site at all, so the webmention would be invalid.
- many sites don't include replies in their home page feed or linked
rel=feeds. for those sites, bridgy's original post discovery wouldn't find POSSEd comments, so it wouldn't know the original comment permalink on your site to link to.
- bridgy users generally want the whole conversation on a post to show up on that post. the vast majority of indieweb CMSes (notably Known and WordPress) don't do this kind of dynamic threading - permalink per comment, but also render them all together on the original post - well or at all. so if we did this, they'd break.
salmentions are arguably the best answer to this. with salmentions, bridgy comments-on-comments could
in-reply-to-link to the bridgy URL for the parent comment, and propagate salmentions all the way up to the original post. sadly, implementing salmentions well is tricky and subtle, so they haven't seen much development or adoption so far. still, that might be the best place to push forward if you're interested in this! more details in #458.