alt Hacker NewsSocial media communities adapt to the constraints of their platform or don't use it. You seem unaffected by the inability to share photos on HN, indicating that's okay for sites that want to be patronized the way HN is. It wouldn't work if you wanted to create a meme channel, but HN doesn't want to be a meme channel and neither does IRC.
it's fitness for purpose. HN works perfectly for what it is used for. it would be unusable for a family or work channel unless that work is programming or something else text heavy which doesn't require sharing graphics. same goes for IRC.
the point is that usecases where media support is needed do exist.