I am not a native speaker, but, in my opinion, because of the fact that the verb, from which this preposition comes from, is "a datori", which actually means "to owe", it cannot be only positive. Think the fact that when we usually owe something to someone, we refer to money. "Eu datoresc banii"= "I owe the money". So, it could be negative. If you want to refer to something "strongly" positive, use the prepositions "mulțumită" (from the verb "a mulțumi"="to thank") or "grație" (from the latin "gratus"="to please", "to be grateful").
The verb is "A datora" and 1st person present is "Eu datorez". "Datorită " is used in positive cases but somehow less positive than for "mulțumită "
For negative things, in Romanian, you have to use "din cauza"! "Datorita" is just for positive construction of the phrase!
Good question! I have seen în cauză, pentru ca and now datorită! Are there any more?! As to the correct usage for each one, I have no idea!