Let's compare it real quick to another area that I don't think is fundamentally all that compelling -- tank stances:
As they existed, tank stances were just a way to play "The Price is Right" (picking when to leave tank stance and never return to it) against your highest Enmity dps because...
- There were no eHP checks against which survival would depend on the tank stance.
- There were no early DPS checks for which one would need to drop enmity in favor of damage early on and make that enmity back up later at cost to overall damage.
- The added defensive value was virtually never an rDPS gain relative [e.g., via extra healer damage] once considering the cost to your own damage.
Fix any of those contexts, though, and avoid the button bloat (you only really need the 1 button we already have now to manage all the agency tank stances have ever provided), and you have what could be pretty damn decent. Instead, though, we simply removed that whole potential aspect of tank agency altogether.
I was more or less okay with tank stances being removed because, by the time they were, they didn't matter, and I associated them with a high button cost. If I had back then the perspective I have now, though... that's much less likely.
In either case, I don't want to see gap closers condemned to the same, especially in a way that makes that much identical atop having less room for skill expression. What's more, though, unlike tank stances, the solution to making gap-closers feel less stale a means of skill expression is a solution that'd help a hell of a lot more than just said gap-closers: