As long as you're talking about government-recognized corporations in that specific context in which they do get special benefits from the state via their "legal fiction" status, then I don't really have beef with you about that. I agree that large companies (not necessarily just corporations but them too) get lots of benefits for the taxes they pay. It's actually a smart investment for Walmart to lobby the government to kick people off their private property rather than buy it on an open market on the premise that the government will collect a lot of taxes from them, taxes they're going to pay anyway so they may as well benefit from government force.
That said, the basic idea of people pooling their investments into one endeavor and divvying it up into property shares based on how much they've invested is just a (albeit complex) contract and doesn't justify them being stolen from. If someone did an agorist version of a corporation, that would be very different and I wouldn't wish violence upon them for it.