Ops cost is only 10 out of 100 Energy, 10%. BH is with talent 8 out of 100 Heat, 8%, which unless they were to make it an even number is as even as it will get. Sorc have it only cost 20 out of 600, 3%, let's be honest it is not out of 500 who wouldn't want an extra 100 resource.
Yes the heal amount is small, but all heals help, especially when you get a heal from something that doesn't normally have one.