Starzz, I have to say, some of the very best coaches I have ever seen yelled at his players at the drop of a hat and very publicly. My own high school basketball coach did that. His impact on my life was profound and exceedingly positive. 33 years later, I still visit with him whenever I am in my home town. The high school coach my two oldest sons have had is as tough as they come and his impact, likewise, is lifelong.
Other coaches have been very effective without saying much or by keeping it positive.
There are lots of styles and sometimes the same style works for one guy and not for another. I'll say this, I would much rather play for a coach who yells at me than sit for a coach who could not be nicer.