If you look at the damage, it's still decent. For a well-geared player, it's damage can rival Intermediate Magic DPS.
Compared to Crash Shot, it isn't limited to a certain number of targets, and the damage is thoroughly spread out.
Again, the classic "assumption of best case". A well geared meleer has spent a few million on their gear. And it assumes they have the skill level and connection to maintain Int magic DPS without dying. The reason why this discussion often fails to go nowhere is because people gloss over the fact that using Interemediate magic is not only safer than using Windmill, but because of the ability to offhand shields without losing damage (obviously Giants don't have this problem though), not to mention not losing 10% of your HP per use, and having a massive MP pool for Mana Shield, it is also far more forgiving of mistakes.
Classic example was Ciar Advance, where you could reduce sextuple aggro down to double aggro if you knew how to do it properly.
And? Mages and even rangers could blow up mobs without getting aggroed at all if played correctly
Especially with the reduced effort put into new content, pet play isn't as vital as it was in Ciar Advance. Mobs often aren't mixed enough to require it, and Assault Slash reduces the thread from ranged attacks. Melee mobs are also retarded, they no longer stall or weave around you to add to confusion, instead just charging forth repeatedly, and sometimes loading Smash to make it even easier.
Shadow mobs are far more mixed than they were in Ciar. Alchemist/Wizard, Range, Melee, and Lancer and Fighter mobs weave around you all the time, and Warrior mobs even more so. Some mobs can bluff Counter, with stationary Defense, leading to your WM bouncing right off and you dying. Ghost of Parth mobs laugh at WM. Oh yeah, you can't remotely threaten a one-shot against Hard Mode mobs outside Tara, and will miss a two-shot if you don't crit with both WMs, unless you have 350+ max damage.
With Advance Heavy Stander you're actually pressed to deal high amounts of damage and protect yourself, instead of just WMWMWMWM MAGMAGMAGMAG FBFBFBFB
That pretty much is advanced heavy stander battles in a nutshell - spam DPS until target is dead. Just replace WM with Smash.
Also, can people stop citing Ranald's in-game text? At least keep in mind that the skill is also called the Crown Jewel of Melee, but that doesn't help the argument they are putting forward does it?