I'm sure even in real life we'll encounter this situation, whereby we like to extend a helping hand, only to find out that we got backstab afterwards.
Besides, this theme had been used by multiple source of story too "big power brings big responsibility", noblesse, etc.
All in all, it's common knowledge that humans are plagued by the 7 aspect of sin, that is gluttony, greed, lust, wrath, pride, sloth and envy.
We human can never had enough, the grass is always greener on the other side, etc.
Sorry for the useless post.