Seems more like a question of degree. Dividends are also taxed as income so ~36% is already paid in tax depoending on the income of the shareholder. Increasing the corporate tax rate to 40% brings the effective tax rate to ~52%.
In my experience there's a more fundamental problem with large companies. In a small company, the best way to succeed as an individual (whatever position you have) is for the company as a whole to succeed. At a very large company, the best way to succeed is to be promoted up the ladder, whatever the cost. This effect is the worst at the levels just below the top: you have everything to lose and nothing to gain by the company being successful. It's far more effective to sabotage your peers and elevate yourself rather than work hard and increase the value of the company by a couple of percentage points.
The thing is, the people that have been there since the beginning still have the mindset of helping the company as a whole succeed, but after enough time and enough people have been rotated out, you're left with people at the top who only care about the politics. To them the company is simply a fixture - it existed before them and will continue to exist regardless of what they do.