I dont think its a good idea.
While the advantages are totally lost on me, if it is about Kenya thumbing its nose at the international order, then I can see where they are coming from; they might be impressed.
If it's to escape external scrutiny of the level of violence that the government or leaders do to the population, they are clearly mistaken.
Alternatively, it might just be loose change for someone to pocket. Whatever fees Kenya pays to ICC.