The designers reason not to include GCC (and other development tools/headers) from the production servers is mainly security. The target users of this all-inclusive distro are regular home and small business users without Linux experience. For more advanced users/developers, development tools package (GCC, kernel headers, some libraries and tools) generally available as an addon devtools per version of SME, or you could use the ones that included in the "mother-distro". For SME 7.0 b4 that is CentOS 4.1