True, this is an important distinction that I neglected to mention.

Nevertheless I don't see liability or tax differences as fundamental: I think that, even if there was no legal concept of a corporation being a (kind of) person with special protections, functionally similar structures could and would arise. We already have liability-waiving EULAs everywhere for software, which 99% of people accept without a second thought; perhaps this concept would be much more widespread.

I also think that most people who complain about "corporations" don't carefully distinguish them from other ways of clumping people together for business reasons, like partnerships or trusts -- I think the resentment is mainly around the size and wealth of these clumps. And I think that the differentially wealth-generating tendency of all these people-clumping arrangements comes primarily from the efficiencies (and additional possibilities) afforded by letting the people in them specialise their work, rather than from liability and tax differences.

But admittedly that's my own speculation.