That math is still pretty close to right for a growing company. Let's say you're the founder of a company with a market cap that makes it to ~$100B. To get from $100M to $100B, the value of the company has to double every year for ten years. So if the tax rate is 25%, for each year the price doubles you lose 12.5% of your shares.

By the end of ten years you have barely a quarter of what you started with. If that was 51%, it's now 13% and the MBAs come to ruin your company.