I strongly disagree. At least in the meaning, you worded it. I think it might get someone into the mindset that he must give it everything in every shot, which may lead to too much muscle tension. If you force yourself to use more power than your skill can handle you are bound to get unenforced errors. I think one should stay relaxed until just before body rotation. I usually hit the ball too much flat when I force myself to add much power. When I stay relaxed and take a proper swing (I shadow swing with panda pong video) I have no problems with most of the strokes. If I get into mindset that I want to kill the ball it flops.
I may word it wrong, but a month ago I started a thread about the choice selection. I worked with that to let my body flow with the ball. I started stopping forcing myself into playing the shot I want, but rather react a little bit more to the ball I have. So far it helped me to stay relaxed and lead to more balls landing on the table. Once you get better at having proper contact with the ball you will be able to generate more and more spin and spin. Start slow, practice consistency, add more power slowly. Try exercises yogi showed. Focus on generating spin and don't focus so much on speed. Speed will come with practice. At least that was the case for me, probably because that will lead to having more "down-force" to pull faster balls on the table.