Er, sorry, I rather meant that profits after dividends would be capped. You can do anything you like with the money—other than keep it in the corporate coffers (or in commercial paper or anything else that's still liquid assets on the balance sheet.)
But yes, you're still right, it wouldn't have the correct effect.
How about a sliding window cap on non-compensation spending, together with a sliding window cap on headcount? So, in a year with record 10x net revenue, you would be allowed to 10x your salaries/bonuses/dividends, but you wouldn't be allowed to multiply your capital costs, or "new" labor costs, by more than, say, 1.3x. (And keep the fixed profit-after-dividend cap, because otherwise the corporation would just hold all its money in the bank until the sliding window grew enough to let it spend it.)
Also, presumably you're talking about new laws in the US here? What stops businesses from just moving their HQ overseas to places with different laws they like better?