The biggest complaint you’ll hear from teams that do write specs is that “nobody reads them.” When nobody reads specs, the people who write them tend to get a little bit cynical. It’s like the old Dilbert cartoon in which engineers use stacks of 4-inch thick specs to build extensions to their cubicles. At your typical big, bureaucratic company, everybody spends months and months writing boring specs. Once the spec is done, it goes up on the shelf, never to be taken down again, and the product is implemented from scratch without any regard to what the spec said, because nobody read the spec, because it was so dang mind-numbing. The very process of writing the spec might have been a good exercise, because it forced everyone, at least, to think over the issues. But the fact that the spec was shelved (unread and unloved) when it was completed makes people feel like it was all a bunch of work for naught.
Getting people to read your specs is the topic of the fourth and final part of my series on functional specifications.