ppm does not constitute CPAN support. It does provide for (some, limited) module installation, but what it provides is only comparable to what is available for other languages, like Java or Python; it is not full CPAN support. Many modules are not available at all, and those that are available are usually rather badly out of date.
This is not entirely ActiveState's fault. They had to make bricks out of straw to provide anything at all for module installation, due to a marked paucity on the host operating system of the sorts of facilities that are normally expected on a POSIX system (e.g., make).