I think a personal motto like that can be exactly the drive some people need, if they have a tendency to feel that they are not going to succeed when all they actually need to do is hang in there at a good pace.
But every person, and every business need, is of course not the same, and I agree that your alternative can be better for many. Some types of work require brute force and power to get through to the ultimate goals, and others would benefit more from flexibility, creativity, and an ability to pace one's self. It can also be a mixture of these things, or some other method altogether.
It's important to consider that there is no one right way for every one and every process. So it's nice to see an alternative to an old mantra many consider imperative and alone in its usefulness.
I would be curious to know what other members consider the most important or universal rules of encouragement for our situations as small business owners.