Acquia has quickly become successful in increasing the exposure of Drupal to "CTO-level" conversations at larger enterprises. Despite the fact that there are numerous examples of big companies using it, Drupal is really still pretty unknown in big organizations - at least when you compare it to commercial, closed-source content management systems (the "incumbents").
As Drupal starts to make inroads in these larger organizations, the incumbents are forced to defend why their expensive proprietary software is better than that "little Drupal project." Hooray! The mere fact that they now must have answers shows that Drupal isn't such a little project anymore, and it is starting to cause real pain to the incumbents. It's now only a matter of time: high quality, powerful open source software with a big community behind it is the biggest threat to any closed-source software. The incumbents are living on borrowed time.
But given that we're now impacting them competitively, we're all about to experience an increasing flow of venomous-sounding FUD coming from these incumbents.