I don't know why either side to this debate is complaining. This spell has its obvious uses. We have many spell gems. I have this and BoS memmed always. You aren't going to always want to use BoS because it costs twice as much mana, and it blacks out your spell gems for a second or so. This is one second (I don't know why everyone is acting like that is a long time. It's not like it is our 4 second heal) , and you can follow it up with BoS or your HoT spell line right after without having your spell gems blacked out.
So there are 4 obvious reasons / situations where this would be used.
1. If you are low on mana (a lower heal than BoS, is better than no heal)
2. If you want to have a little more healing than just BoS (use this, followed by BoS)
3. If you need to refresh your HoT spell and / or refresh Ward of Tunare, but still want a heal (if you cast BoS, it will take a long time in between refreshing everything, but this way, you can cast this heal, then Ward, then HoT, boom, boom, boom)
4. Lastly, and probably most obviously, maybe you just don't need that much of a heal, or don't want to use an unnecessary amount of mana. It is what it is. A good SMALL heal.
I don't understand what everyone's beef with this spell is. This and BoS are 2 TOTALLY different spells. Just use both, and be happy you have options. It's fine.