So wait, you are telling me that it only gives you a 0.1 second advantage over not using windower stuff? Oh ho ho ho, i'll tell you something instead. I think you don't know how to use the tools Windower provides correctly

Maybe you haven't realized the power that exact numbers have over aproximates. Want an example?
Ultima. I've seen Ultima's AoE move being stuned easily because everyone knows when it's gonna hit. The second you see the HP% at 80, you know what you'll be doing the next second. If you couldn't see the total HP%, you wouldn't be able to distinguish between 80% and 85% by just looking at a tiny health bar. That means that you either start randomly stunning or become slopier in the rest of the things you need to do.
More? I leveled BST (and i loved it) as solo before the exp reduction fix, so we had to release pets before kills. With the % HP thing i could easily see exactly how a badly landed rampage would take from a mob after a couple fights, meaning i could precisely know when to release without having a single chance of messing my kills and still being optimal instead of risking to either: a) Release and Rampage too early so i would depend on crits to kill or b) release to late and risk my pet landing a double attack crit and killing the prey for a 30% penalty.
And this is only for the little nifty thing that seeing the %HP is. There's so much more.
Is your argument that these are just "small little details?" You kidding me, right? If small details aren't important, why do RDMs or WARs push so much to get the most optimun gear? Are you gonna tell me that +4 extra MND or STR is "a little detail"? Use the same ruler for everything you do, else you are just having a two faced moral.
I honestly don't care if you want to kid yourself, windower does provide an advantage and
the whole point of the argument was that the devs cannot and will not design mobs that consider such advantages.
I also don't care if everyone here and out wants to use all the windower bells, they are great, some are really stress saver, but at least have the bravery of accepting you do have an edge. "Nah, i could do without it" sounds like an addict talking about it's addiction before accepting it. Keep at it.