Defoe art suffers from a number of drawbacks: (i) his plots are weak; there are too many incidents, rather weakly inter-linked, and (ii) his character are not sufficiently individualized; Robinson, Moll, Roxana, etc.
May be an advance over the character of earlier fiction, but titer are not very real. They still want the touch of genius. His descriptions may be sufficient, but they have no decorative or poetic quality. Defoe is, no doubt, fond of dialogue, but his dialogue is spoiled by his shapeless style.