> These folks already paid their fair share of income and sales taxes

That would only matter had they chosen not to incorporate, once they do (or buy into it), then they should accept the rules, warts and all. As you said, a corporation is a purely legal notion with upsides (limited liability) and downsides (pay the bloody taxes, c'mon)

In this case, it wouldn't really be in Apple's interest to say we should treat them as just individual people who happen to work together. They're only getting a custom property-tax abatement deal because they're a large and important corporation that's treated differently than regular people are. If a bunch of separate individuals had bought parts of this land and each ran small-scale businesses on it, they'd be paying regular property-tax rates, and no state legislator would be rushing to grant them a special carve-out.

There are other forms of business if the taxation issues of being a corporation are undesirable. Most big firms are corporations though because the benefits are worth those costs.

This implies that large corporations act like normal people, which really isn't the case.

The shareholders of publicly traded companies expect exponential growth, and if the managers and owners don't provide that growth, the board of directors kicks them out and replaces them with someone who will drive that growth, regardless of the effect on the workers. When corporations naturally behave sociopathically, it's only natural to treat them differently from normal people.

Edit: To those downvoting me, could you please explain why? If I'm interpreting something incorrectly, I would like to know.

I did not down vote you but most stock owners do not expect exponential growth from the company. They expect linear dividends, which they can reinvest to get exponential growth.