Yes Roy, you may be correct but, its not like I haven't tread dangerous ground before. Challenging the orthodoxy of an established belief system can at times prove perilous.
It has at least, proven to be an entertaining "conversation."
Wayne van Zwoll is certainly a highly regarded and respected individual (he actually runs a outdoors skills camp for women not far from my home in Wyoming) and his advise rings true for the intended core audience to whom he is writing, i.e. people lacking basic optics knowledge and experience who are trying to make good, educated, first purchases. This is also the core audience for almost every magazine article he (and other "experts") writes. Actually, if you read what I have posted carefully you will find that I am in general agreement with their comments as they pertain to such individuals. My point has only been that this does not represent an infallible Truth and that, with greater experience and the learning of proper holding, bracing, and steadying techniques, higher magnifications can be used to great satisfaction. Such processes are not difficult to learn and it is disingenuous to state that lower power is better based solely on the criterion you have given. They are admittedly easier to use for someone lacking experience but, easier is not the same as better.
It's like learning how to shoot. Anyone can learn to throw up a rifle, look through the scope, and pull the trigger. Such an individual can even learn to shoot accurately enough to hit a 100 yard bulls-eye with sufficient success to be able to then successfully hunt a variety of game animals. In truth, the majority of shooters probably do little beyond this in their attempts at accuracy. But, if you want to become consistently accurate to any marked degree there are certain techniques that must be employed. These techniques apply to such things as:
Proper control of one's breathing
Proper body positioning for maximum stability
Proper Head positioning
Proper gripping of the firearm
Proper sighting in methods
Proper trigger control
Go to a shooting match and you will see that the competitors who are consistently in the top rankings all use the same basic shooting form and control techniques. Even Mr. van Zwoll will tell you this. Don't believe me? Go read one of his books on rifle accuracy in which he says exactly this.
This principle is the same for any skill. Anyone can pick up a basketball and learn to dribble around a court. If they want to be competetive however, they have to learn the "fundamentals" of playing the game. And so it goes with any activity requiring a measure of skill. Using sporting optics is no different and a person who learns to use proper holding, bracing, steadying, gripping, etc. techiques will find that (with practice) they can successfully use greater magnification than they first anticipated was possible.
By the way, I spent 5 years working for the largest contact lens retailer in the world and I learned one heck of a lot about contact lenses in that time. I could tell you all about the various major manufacturers, their products, and the prescription parameters covered by those products. I could even tell you which brands and models were the most popular. Despite that, you would be ill advised to ask me which were the "best" lenses, how to best care for those lenses, or how to even get the darn things on your eye.