Because there isn't a corporation in the country that actually pays the full corporate tax, some even end up with tax CREDITS. There are so many loopholes in corporate tax that that rate is a useless number.
Even if we pretend that the corporate tax rates are worth the paper they're printed on, the fact that the corporation's profits are taxed before they distribute dividends doesn't mean a goddamn thing for the taxes Buffett pays on his income. The corporation is its own entity, it needs to pay taxes just like everyone else. Taxing the corporation on its profits and then taxing shareholders for their income from dividends is NOT double taxation.
You apparently are under misinformation regarding what a profit is and how corporations pay taxes and dividends... Dividends come from profits by definition ... a corporation will NOT pay dividends when they shelter all their income to look as if they earned no money and yes corporations do this and a lot of these are for very frivolous things.... Warren Buffet exploits every thing he possibly can to maximize this and he pays accordingly with a fleet of highly trained accountants.... when Warren Buffet speaks he makes money it is a simple fact, he has motivations beyond just being a nice guy to want him and his peers to pay more in taxes, he will profit more from this in ways you or I couldn't even fathom... or he wouldn't even say it. If he feels so "kind-hearted" then why doesn't he just go and give 90% more of his and his companies income to the government... they don't need it and the government can use that money better than he can right?
That's a highly illogical argument. There's no reason for him to give money away so that all can benefit while he alone foots the bill.
I don't think you understand the complexity of corporate tax structure. There is a reason corporations have multiple divisions and organizations within them. They usually have an intentional loss leader (like GE's GE Capital) that consistantly loses tremendous amounts of money for tax write-off purposes so that the company as a whole comes up tax neutral (or even with the government owing them money).
but wait your money was already taxed
No, it wasn't. The COMPANY'S money was already taxed, not my money. The company is a separate entity. Shareholders are partial owners of the company, but the company is its own being. The company pays its taxes and the individual owner must pay his own taxes. That's not double taxation, that's everyone paying their taxes.