Agreed. You should have a very proven path to generate revenue, outside of licensing, if you go the open source route. Companies who try to go it "halfway" by releasing a core product as OSS and then try to introduce closed-source addons have a tough time getting by on services while they try to prove that the addon is worth the extra cost: ArsDigita had to try this route in order to grow the business, and they burned through $20M before getting sold for pennies on the dollar to Red Hat.

In short, fantastic tools with which to build a business, but as a selling point of a product...once you take the genie out of the bottle, you often find yourself wishing you could put it back in later.