In a sense, the first (if not necessarily the prime) function of a novelist, of ANY artist, is to entertain. If the poem, painting, play or novel does not immediately engage one's surface interest then it has failed. Whatever else it may or may not be, art is also entertainment. Bad art fails to entertain. Good art does something in addition.
The popular distinction between 'constructive' and 'destructive' criticism is a sentimentality: the mind too weak to perceive in what respects the bad fails is not strong enough to appreciate in what the good succeeds. To be without discrimination is to be unable to praise. The critic who lets you know that he always looks for something to like in works he discusses is not telling you anything about the works or about art; he is saying 'see what a nice person I am.
When sonneteering Wordsworth re-creates the landing of Mary Queen of Scots at the mouth of the Derwent -Dear to the Loves, and to the Graces vowed,The Queen drew back the wimple that she wore- he unveils nothing less than a canvas by Rubens, baroque master of baroque masters; this is the landing of a TRAGIC Marie de Medicis.Yet so receptive was the English ear to sheep-Wordsworth's perverse 'Enough of Art' that it is not any of these works of supreme art, these master-sonnets of English literature, that are sold as picture postcards, with the text in lieu of the view, in the Lake District! it is those eternally, infernally sprightly Daffodils.