As per other comments, I'm not entirely sure what your sentence structure really permits, but if you need a word like detestability then you may be happy with despicability.
despicable adjective
- deserving to be despised : so worthless or obnoxious as to rouse moral indignation
- "despicable behavior"
Merriam-Webster
The noun form despicability is not especially common, but is certainly known:
despicability
- a despicable quality or aspect
- … when writers present to the world someone as unsympathetic as John Self or Humbert Humbert, they tend to sweeten the pill by offsetting the character's despicability with likeable qualities: irony, japery, or a fancy prose style. — David Annand, The (London) Sunday Telegraph, 4 May 2014
Merriam-Webster
Based on this NGram, it looks like despicable is around 500 times more common than despicability