Same reason Spez is still doing damage control over 3% of his userbase leaving, up to and including signing up more bots to boost traffic and denounce the protests. It's not like he's losing a whole lot, he's kept multimillions of users (human and otherwise) to make his shareholders happy and his site will stumble along pretty ok for years. But in capitalism, especially the ad-driven digital sphere, eyes are everything.

Federating with the rest of us IS a blip in the grand scheme, but so was 3%. The fediverse existing outside of Threads carries the very significant risk that their users will sign up for their service and see the other platforms that are just as nice without being ad-soaked, subscription-based, and demanding your real name while they sell every ounce of your info.

One of us is going to be leeching users from the other and meta will not like this, so they're liable to make damn sure it's them. It wouldn't really shock me to see them neglect to upkeep federation with non-meta instances while they attempt to charm users away with a recognizable, high-traffic platform full of bells and whistles.

EEE doesn't need to be an intentional attack. They only seek profit.

• It is profitable to adapt an already mature protocol like XMPP or ActivityPub instead of creating their own from scratch (BlueSky is creating their own protocol, and they're still in beta and probably will never catch up to Threads because of this).
• It is profitable to create new features that increase the engagement of the users. And since they don't care for the community, only for themselves, these features are never released as open source and incorporated into the protocol.
• And if it's profitable to wall their instance (like WhatsApp using XMPP but not federating with anyone else) or to close it (like Google killing Google Talk), they will do it. They will not care if their actions negatively affect the rest of the fediverse.

The fediverse is virgin soil, Meta trying to get there before others is expectable, if only to poison the wells.