Companies should have political power if you're going to tax them. No taxation without representation, right?
Yeah their employees have representation. Their employees also pay the same taxes as non-employees. Since the taxes their company pays are in addition to taxes the employees already pay as individuals, it needs to be counterbalanced by additional representation.
The whole tax charade is pointless anyway. It doesn't matter whether you tax personal income or corporate profits. If you accomplished the Bernie supporters' dream and eliminated all income taxes and converted them to corporate taxes, people would not suddenly become wealthier. Companies would just be forced to decrease wages and increase prices to pay for the taxes, meaning the average individual's purchasing power would be the same before and after the tax change. Wealth is proportional to productivity, not income. So unless your change increases productivity, it cannot increase average wealth. Artificially increasing income without increasing productivity just causes your currency to become worth less (prices will rise to compensate) so that there's no net change in real wealth (purchasing power).
So just pick whichever tax is easiest to collect and use that as your sole source of government revenue. Taxing a gazillion different things is just wasteful inefficiency - like using a thousand teaspoons to remove a percentage of a bathtub's water, instead of a single bucket. Also note that if you don't want to violate the "no taxation without representation" principle, and you want a progressive tax structure, the tax has to be on personal income. If you shifted all taxes to corporations, their price increases would be equivalent to a flat tax. And higher-income management controls wages and will be most reluctant to cut their own salaries. So the net result of shifting all taxes to corporations would be regressive compared to the current taxation system of income + corporate taxes. The only way to control a progressive tax system is zero corporate taxes, with all taxes being on income, and ratchet up the income tax rate on the higher income brackets.
It's amazing how people who reject the concept of corporate personhood hypocritically insist on treating a corporation as a person. They're not people. They're just a group of people who've decided to work and act together. If you have a beef with how a corporation is behaving, aim your ire at the people controlling that behavior. If you don't like how much profit a company is making, focus your remedy on the people who are receiving that profit from the corporation as distributions or dividends. Thinking of a corporation as a person just reinforces the notion that corporate personhood carries with it rights (e.g. free speech) and duties (e.g. paying taxes).