Hi Arno, we'll agree to disagree on the eccentric portions of deadlifts. I believe that it is extremely valuable, especially for Romanian deadlifts. If you are lifting maximally, then yes you shouldn't prioritize the eccentric portion - that may be dangerous. For most folks, however, a moderate load with a deadlift (focusing more on an endurance rep range) can do wonders for the posterior chain. If you have a solid article stating otherwise, I'd love to read it!

Keep in mind that this is an article based on personal experience. All those other training principles are very important, yes, but tempo issues are something that I've run into A LOT in my own personal trainer jouney recently. It does not mean it's the most important or common mistake for all gym-goers.

Thanks so much for taking the time to read and leave such a thoughtful comment. I appreciate it!