GPL works just great for documentation

Code is text, just like documentation. They are both usually stored in human readable form and compiled into machine readable form before use. Many documentation languages, like TeX and PS, are simply programing languages optimized for generating documentation. Others, like html, come with a full featured programming language embedded. Most modern computer languages support writing documentation and source code as a single entity, that can be used by different compilers to generate either a documentation document or a running program.

GPL concepts like preferred format and prohibiting further restrictions are equally applicable to code and documentation. The clause about selling GPLed works is more relevant for documentation than for software; it allows you to charge money for high quality printed versions of a text, while forcing you to include the source version of the text. The company I work for releases all documentation under GPL3. The Debian project recommends the GPL for documentation (http://www.debian.org/vote/2006/vote_001.en.html#amendmen...).

Corbet, it seems to me that the only argument against using the GPL for documentation is that FSF says so, please elaborate on why you consider the GPL «a poor fit for text».