A lot of people dislike it for the privacy nightmare that it is and feel the threat of an EEE attack. This will also probably not be the last time that a big corporation will insert itself in the Fediverse.
However, people also say that it will help get ActivityPub and the Fediverse go more mainstream and say that corporations don’t have that much influence on the Fediverse since people are in control of their own servers.
What a lot of posts have in common is that they want some kind of action to be taken, whether it’d be mass defederating from Threads, or accept them in some way that does not harm the Fediverse as much.
What actions can we take to deal with Threads?
For me it is primarily Meta. The users are to be avoided only on the grounds that they’re tacitly supporting Meta’s antisocial goals. If the same people came in from a non-sociopathic provider I’d be far more open to them.