I don't hate fun. I don't hate expansion of the Fediverse.
I do hate Meta, and with very good cause - anyone who's been in the industry for awhile is well aware of their philosophy when it comes to users (cattle). I do not use their services and I do not trust them with my data.
On a larger level, Meta's strategy in the Fediverse, given their corporate philosophy and previous actions, reeks of the "embrace, extend and extinguish" model developed by Microsoft in the mid-90s, and the size of their user base immediately makes them one of the biggest organizations in the Fediverse - Meta's influence will be significant when it comes to evolving the ActivityPub protocol.
Finally, Threads is just an inferior product to what's already available in the Fediverse. My personal favorite - go and check out Kbin for a bit. Even without the Meta audience, the Fediverse already has better alternatives available that don't cost you your privacy.