One doesn't seize power without force, in most cases (waiting for the Gandhi reference...) So if one assumes maintaining a government, probably a military is required. That's gross. Not to say that martial formations might be needed at times, but a standing military class of specialists seems to carry the seeds of hierarchy and domination pretty inherently, at least to me.
As to corporations, the Bolsheviks started with the goal of eliminating private ownership, and ended up with state capitalism. Was it better? Was it worse? Depends on your perspective, but it was definitely shitty.
The state is amorphous. It isn't just politicians and government, it is the apparatus that enable and facilitate large scale social organization, and this includes corporations and the military, but also could include unions who play by the rules of the state and corporations (and if they don't, get crushed by the military).
It all goes hand in hand. Anarchists are against all of it.