Corporations aren't necessarily bad because they're corporations. There are conflicting interests at work. You have to understand the difference between shareholders and stakeholders. Shareholders provide the financial lifeblood to get the company off the ground, and Corporate executives have a fiduciary duty to their shareholders. You could say that a corporation's employees are the stakeholders (there is some ethical duty to these people- you provide payment in exchange for services, but an employer/employee relationship isn't purely transactional. An employee's livelihood depends on that paycheck), and that corporate executives need to be held responsible to them. The problem is that when there is tension between serving those two sets of interests, it's usually the stakeholders who get the shaft. If revenue isn't growing in line with what executives promised shareholders, a fast way to get closer is by either pushing your employees harder to produce more or to cut overhead by eliminating jobs.

The thing that people hate about corporations isn't that this system exists- it's that when shit goes poorly in a corporate environment, the rank-and file are hit the fastest and the hardest, even though they are the lifeblood of the company. A lot of corporations will pull in Big 3 MBAs to change the "company culture" and fire a bunch of programmers/craft laborers/writers/admins/insert any job between the entry level and the C-Suite. Then, when sales don't improve, those MBAs are moved around laterally and the rank and file get laid off, rinse and repeat.

"Bad things" corporations do usually aren't illegal, just ethically questionable and so over-determined (who's fault is this specifically? Middle management, upper management, board members?) that blame attribution is next to impossible. It's like if you get fucked over by your corporate employer, you are absolutely powerless to have your voice heard, and the closest thing you get an a dispassionate HR lady who cares, but who is also under the thumb of they who pay the bills.