[Fantastic_T]

>There is no fundamental relationship between taxing profit and investment.

The sole motivation for investment is profit. As profit declines, fewer investments are justified by the projected ROI.

>If a company makes 20 million a year after tax it is not going to drop everything and stop making a profit at all if it starts making 15 million a year after tax.

There's no way a party can know beforehand how much profit, if any, there will be. The estimated possibility of profit is adjusted for the estimated risk of loss, to get the projected ROI. Higher taxes reduce the projected ROI, because they reduce the size of the possible profit.