should considered harmful
When I was young, I learned a few words to never say. The entire concept of "bad words" always seemed funny and weird. It really doesn't make much sense to disallow the utterance of a few key phonetic components, as if these somehow could really be inexcusably more offensive than other more coherent and meaningful strings of sound.
As I've played with the character of a personal dialect, I came to my own decision to swear less because, often, swearing simply means you couldn't think of a more articulate way to express yourself. To stretch an analogy, swearing is to communicating as drinking is to having fun. It might seem cool when you first try it, but in the end it's more a pain than a panacea.
Finally getting to the point: this post is not all about the classically crude curses, but rather about the existence of a few choice words - well, one in particular so far - that might actually deserve all the hullabaloo of a terminological taboo: the word "should". It is extraordinarily easy to invoke this word as a means of detached and elitist censure.
So what makes a truly bad word? I proffer that a word which strongly implies, or depends upon, the acceptance of questionable ideas as a basis for its meaning, is a word which allows for easy abuse. In the case of should, the questionable idea is that of either a universally-agreed moral code, or a moral expert. A phrase like "you should never burp at dinner" carries with it the weight of unjustified authority. In fact, such advice might leave you a rude dinner guest in some cultures.
To be constructive, let's consider what can be said instead. If you want to avoid the embarrassment of someone new to the dining customs of the U.S., you might say that many American hosts consider it rude to burp loudly during meals. If you're teaching your child about your moral position on theft (let's assume you're against it), you could explain the legal, material, and emotional consequences of stealing, along with your own personal disapproval. If you have your own moral decisions that you've reached rationally, then it's always possible to express yourself without resorting to vague implied universal standards.
Am I so vulgar as to say you should never say should? Absolutely not -- I'm really trying to emphasize personal choice and rationality here, after all. So, with respect to any readers who chuckle at such lexical eccentricities, this post aims at nothing more than a reminder to speak responsibly :)