Since I can't be bothered to do real research, I'll just point out that this Yahoo answer says that the quote is spoken by Lord Darlington. Oscar Wilde was a humorist and an entertainer. He makes amusing characters. His characters say amusing things.

Do not read too much into this quote and, without further evidence, I would not attribute this philosophy to Oscar Wilde himself.

(I haven't read Lady Windermere's Fan, where this if from, but this sounds very much like something Lord Henry from The Picture of Dorian Gray would say. And Lord Henry is one of the main causes of the Dorian's fall from grace in this book; he's not exactly a very positive character but certainly an entertainingly cynical one!)