It's a bit of a difficult one.

If I were snoring or otherwise disturbing other passengers I would like to be woken up and told about it. As I see it, I have no desire (or right) to cause undue disturbance or inconvenience to others, whether it is done consciously not not, and I would prefer to be woken up and told than to continue to be a nuisance and I would thank whoever wakes me to tell me. If it turns out that I snore loudly though, I would stop sleeping on board. That is my personal position.

However, I wouldn't wake someone up on the basis that they are causing nuisance unless it is someone I know very well (in which case I certainly would intervene), or they are somehow doing themselves serious harm.