What if Tanks were designed like Healers?

[Renathras]

Instead it has jaded vets from other healers

Yeah, but that's the point: If we change the other three back to their SB incarnations in 7.0 (not sure WHMs would be thrilled about being worthless in basically all content, but I guess they already are compared to other Healers, so nothing will have changed there; they'll just be the one Healer unable to clear some content, I guess? Because apparently that's good game design!), then those jaded vets from those other Healer Jobs would simply be able to pick up their old Job and no longer need the new one.

Is that the numbers that we have seen from Wayback Machine,

Correct, the only numbers we have as no one else was able to provide any alternate data-set.

Note that, at the time, most of the playerbase did not do Savage (or even Extremes) and large portions of the Healer community used Cleric Stance for soloing only. It's also worth noting that DPS Jobs in HW made up only 53% of the Jobs overall (7/13) while they make up 59% in ShB (10/17) and still make up 58% today (11/19). By contrast, Healers made up 23% (3/13), 18% (3/17), and 21% (4/19) of the Jobs in those same periods. So if Job ratio is at all active in player role count (and it does likely have some effect; new Jobs in a role do tend to boost participation in that role for at least a little while), then one would expect the number of Healers to decrease going from HW to SB to ShB. Despite this, Healer numbers actually seemed to have gone up from SB to ShB, which also opposes the narrative that Healers as a whole were alienated by the ShB changes and left the role. That seems not to have occurred, and SB seems to have been the low point.

It'd be nice if we had some kind of official census, though, to really see trends more accurately instead of having to use imperfect metrics in attempts to piece together things.