The Esoteric Knight is set up to blend martial (and specifically fighter) feats at odd levels with occult spell progression and mystic combat abilities that are mostly activated by using up occult spell slots at even levels. It is set up so that a Kineticist can substitute wild talent and infusion progression for the occult spell progression and accumulating burn for using up spell slots. The drawbacks to this class are the spell/talent/infusion progression (only at even levels) and the lack of progression for any other features of your original base occult class. It works best for a Fighter who wants to dabble in occult stuff.
The Ritualist prestige class lacks the Kineticist references of the Esoteric Knight and thus is useless to Kineticists.