Things that you might not always be welcome to cure are Blindeness and defness.
Seeing that you are not a fighting guild, you find no use to something like that. We, however, do... You can not go around taking away peoples defences. This might later lead to them beeing killed by a evil person. (Not nice)
Some animists ask before they cure. Is this insomnia self inposed? etc.
Sorry if I seem rude. But those are the facts!
Mage Lord Tragnarion.