Wiktionary
unbeneficial
a. Not beneficial.
Usage examples of "unbeneficial".
I regret that I have been seduced by unbeneficial and decadent thought.
Klinzhaii exception appears to have derived from interaction with alien races where such communication phrases are essential to avoiding conflict where it is actually unbeneficial to the nature of the situation, despite the Klingon penchant for either starting or finishing such conflicts!
While certain behaviors or traits of the person may be unbeneficial, the person as a whole is always GOOD!