I've built nearly a dozen small-to-medium-sized business sites using Drupal, and I don't see a major reason to stop. Granted, Drupal's stock e-commerce functionality is rather basic, but between its continued development and Ubercart, I find that I can get what I need fairly painlessly.

I don't think I could do a massive site in Drupal, but that's only because I do my work solo. ;-) But for small-to-medium-sized sites, it's easily my go-to CMS.