“The”, not “a”.

There is a chasm of difference between “I care about this problem and want to solve it, but I also need to think how to make it sustainable” and “I don’t really care what I’m tackling, as long as I make bank”.

Both exist. The second one is ever more the norm.

A healthy business uses revenue to pay bills, employees, etc.

Using profit to pay for those things is what we call gambling.