Meanwhile this is the normal, expected, and well-received behavior on ATproto. Every platform defines its own lexicon and can optionally support others. It wouldn't make sense for a blogging platform like (for example) Leaflet to show Bluesky posts the same way it shows blog posts. And apps can be selective too: Skylight only shows video posts. It's exactly how it should be for a video app.

The "account" then is just the data on your PDS with as many views into it as someone wants to develop. If I'm browsing (viewing) an account (subset of data) through a platform or app devoted to one type of content (data), I only want to see that kind of content in the main timeline. I can always pull out something like ATExplore or PDSls if I want to see everything.

The complaint only makes sense for a protocol that expects you to make a new account for a new platform and has limited portability. It doesn't make sense when an "account" is just a view into data, no more morally compromised than an SQL query. I'm skeptical the movement to revive the dead half of ActivityPub that could enable similar functionality will go anywhere, but I am rooting for the folks behind it.