I'm not really sure about other healing classes. My problems with Alacrity are referring to Operative healing only, since we have one spell which is affected by it, two if you count Kolto Infusion. If it added HoT ticks or reduced the GCD on instant-cast spells, then it would be a *lot* more useful. As it stands, it's a subpar stat.
It's certainly not optimal. Though for a Consular it's considerably more effective. I haven't looked at how it interacts with our unchanneled HoT, but it affects four of our healing spells certainly (only three that get much consistent usage) which seems like a distinct advantage. That said, since through-put is really capped by GCDs and our casting regen model, it doesn't really cause a huge spike in through-put, it's more of an added margin of error. e.g. I can wait an extra second before choosing to cast Deliverance which may allow me to determine a different ability is more appropriate. That said, it's still sub-optimal because stats should be targeted toward maximum effectiveness, not maximum down-time.
It's just annoying because most crit mods came with alacrity on them. It felt hard to avoid it. But that's just me feeling self-conscious.