I used to detest William Morris, maybe as a reaction to my parents overly patterned home. Since moving out, my opinions have changed about a great deal of things, not least about Morris.

At their worst, patterns clash and overcrowd a space. When used with compositional insight, for example next to block colours and white spaces (not the same thing!), they take on quite a presence.
He was also quoted to have said "have nothing in your house that you do not know to be useful, or believe to be beautiful", which I count among my many mantras (can one have more than one of those?).