Icy-veins created some largely singular, one-size-fits-all guides per HotS character (which, by the way, they're pretty open about) --which is really just to say, they didn't go though the trouble of making multiple separate guides per character-- and thus all measurement is bad?
I think you've skipped a step or three in that reasoning there.
Yes, people can be overly fixated on minute advantages. You know they do when they don't information, though? They fixate on presumed advantages, believing them to be still more sizable and relevant than they are to an even greater gap from what is reasonable.
Remember Stormblood before fflogs switched from raw DPS to rDPS as their primary metric (you'd have to go to xivhero and link the particular fflog for it to calculate the rDPS)?
People would swear up and down that NIN/DRG/MCH/BRD and SMN/DRG/MCH/BRD were by far and away the best comps because of their "synergy" and that anyone trying to play Monk, Samurai, Black Mage, or Red Mage, even in their optimal teams, were "kinda griefing, bruh." Turned out the jobs' rDPS, though, was actually incredibly balanced by late Stormblood; the presumed "advantages" that were pushing people towards particular metas, fell between inexistent and irrelevant. And that would have been common knowledge if people actually looked into the numbers instead of assuming that the more "selfish" jobs couldn't possibly make up for their rDPS debt with their raw numbers.
It was a difference of having a number (the numeric value of buffs applied minus buffs received) or not. That was it. One chart included the number/factor that the other lacked.
Seeing jobs' rDPS might still underplay the value of "selfish" DPS (as those who do half the work of giving the buffers their rDPS contribution by maximally exploiting those buffs), but it's no rocket-science to go from looking at one chart without those numbers and still thinking "SAM might be doing stupid high damage but it's all fake and they actually underperform Bard" to looking at the other and seeing that, no, even when given no credit for exploiting those buffs, SAM is still doing just fine for the moment. You can take A and B (the ability to exploit buffs and the ability to, at net value, give them) and very easily eyeball job balance from between the two graphic organizers given to you. Those chart's conclusion, at the time: All jobs were actually way more closely competitive than they were rumored to be.
Granted, it still took almost another year just for people to stop treating a lack of raid buffs as an incurable disease just because those numbers be scary while ill-informed maxims are apparently not?