Easy to say as a Ret Pally that basically stops doing damage when not attacking. But if you’re a Balance Druid that can’t stop their DoTs ticking or prevent Moons from falling on enemies, a Fire Mage with Flame Patches down and Ignites spread around, or an Assassination Rogue whose bleeds might suddenly kill a whole bunch of dogs in Waycrest all at once (not that I ever wiped a group this way yesterday or anything), then “throttle” isn’t quite so simple or effective.
Not to mention that there are some specs like Havoc and Frost (mage) whose damage is overwhelmingly cleave or AoE-based, and lose a massive proportion of their damage if they have to switch to single-target on a higher health target while stacks clear. I mean, if the point of making large pulls is that it’s more efficient for DPS to blast down more mobs at once, then pulling such that DPS are having to (as well as they can) throttle damage for several seconds at a time is a bit counter-productive.
I think it’s perfectly fine for affixes to change certain things like how you approach a dungeon. In the case of Bursting, I think the tank can actually control a decent amount of the aggravation for either the DPS or the healer by staggering pulls. Other than some spots with large fixed pulls (e.g. Everbloom Lashers), just letting one pull get down in health a bit before making the next one can easily do a lot of work in terms of naturally smoothing stacks out.
Throttling is not fun, but you need to do it when necessary. But I think in most cases, dungeons can be pulled in a way that makes it less painful for everyone.