perhaps it hadn't occurred to you that buying clothes helps our economy, shops provide employment, those people people pay tax, so it's all grist for the mill. And many like myself will donate garments they no longer can get into, that money goes to charities, so helping poorer countries, and charities here, win win. M&S has been losing touch because of the ranges on offer, and sadly some of the problem has been outsourcing their manufacture overseas, goods they sell are not always made as well as they used to be, and sizing of the clothes for men and women has gone the way of the dodo. I could rely on their clothes fitting me, they don't now, so i buy little from them, not to mention their prices have risen considerably too.
by the way many people live alone, and men shop in M&S for food too, perhaps the idea of the little woman of the house cooking the meal for the family is a bit outdated, not a little sexist.