frankly I don’t see the point other than as an ideological protest

I don't think it's something to take that lightly. Problem is the EEE (embrace, extend, extinguish) that corporations are so good at realizing. The ActivityPub protocol the Fediverse is built on is public so anyone can use it. There's nothing to stop corporations from using it however they want. They can exert influence on ActivityPub much has they have on public standards in the past. That doesn't mean we should happily allow their profiteering to infiltrate our communities. It will destroy them.