That's what I took away from CMSwatch's article by guest analyst Apoory Durga, who said of Drupal:
...[Thousands of third-party Drupal] modules could be your biggest problem...because many times, module upgrades do not keep pace with Drupal upgrades. Even though Drupal has released version 6.2, many of the more popular modules are still on 5.x...[which] modules...are necessary for building...social publishing applications.
I suppose this is a problem in a way, but what a great problem to have, especially if you're Acquia, the open-source company founded by Drupal's founder, Dries Buytaert. Acquia's business is precisely to take the guesswork out of deployment of the core Drupal system as well as these third-party modules, as the article suggests but perhaps doesn't emphasize enough.
It is, in other words, the very complexity of choice that Drupal offers which provides Acquia with such a rich commercial opportunity while staying true to its open-source ideals. Foster simplicity in the midst of complexity, and charge people for that service. It works for Red Hat. I assume it will work for Acquia, too.