The newly discovered singing star Susan Boyle has a lovely voice, and acres of newsprint is devoted to it - deservedly so. Acres of newsprint is also devoted to her appearance and family background, in particular the fact that she is a spinster.
I remember sitting in church as a child listening to the banns being read. Women were described as 'spinster of this parish'. Most of them were probably only in their twenties. I don't know if the word spinster is still used in church now, I'm ashamed to say, but I do know that the word spinster is used pejoratively these days. When did you last hear Kylie Minogue described as an eligible spinster? When spinster is accompanied by an adjective, that adjective is usually something like dowdy, frumpy, frustrated, sex-starved, repressed or dried-up. The word bachelor is rarely accompanied by such negative adjectives. Indeed, judging by the examples in the British National Corpus, a bachelor is often eligible and debonaire, although he might also be a confirmed bachelor, or an eternal bachelor.
The Oxford English Dictionary makes clear that spinster could once refer to men as well as women; it was an occupation ie one who spins. It became the legal term for an unmarried woman in the 17th century. The OED's definition recognises the negative undertones beneath the word: "A woman still unmarried; esp. one beyond the usual age for marriage, an old maid".