It's not the additional hire that gets in the way. Taxes represent additional costs. Even trying to maintain a current level the tax has to come from somewhere. Those with the money invested (be it an individual or shareholders) require a certain return on their investment or the money goes somewhere else. There is a point where if the risk is too high it's not worth the return. In order to mitigate that, companies need to make a certain amount of profit to justify the risk of capital. So in order to maintain the return in a situation of added cost (whatever it is, whether it's gasoline or taxes or raw material), you have two choices: 1) raise your prices and/or 2) cut your costs. You can't generally raise prices more than your competitor, so that avenue is limited. It's usually a combination of those two things.
If you choose to reduce your profit margin, there comes a time when it's a better risk to put your money in a bank than to risk it in trying to grow a business.
This thread has obviously diverged wildly from where it started, but oh well....