Huh? If a C-corp makes $200k and pays out $100k as salary to the sole owner/shareholder and keeps $100k in the business, the shareholder will pay payroll taxes and personal income tax on that $100k salary, and the corporation will pay corporate income tax on the remaining $100k.
OPs characterization seems correct to me. (That you pay taxes once at the corporate level, and once at the personal level.)
You pay once at the corporate level and once at the personal level, but apparently not twice on the same dollar (which was how I understood tvladeck's comment).
Double taxation means twice on the same dollar. The $100k in the business gets taxed at the business rate once. Its never taxed again unless distributed as dividends, unless you count payroll taxes if paid out as salaries.
The C corp's money is not owned by the shareholders until it is distributed as a dividend. That is where the double tax comes into play since that money was already taxed at the corporate level and then it will be taxed again at the personal level.
OPs characterization seems correct to me. (That you pay taxes once at the corporate level, and once at the personal level.)