I think he hit th enail on the head - how many times do you see someone looking for an OSS aka "free" counterpart to a CSS aka "cost money" product? They're looking for free as in no cost, not as in I can mod it.
You're generalizing based on your own opinion or the opinions of people you know. In the circles I travel within, the prevailing taste is the opposite. The first thing we look for when doing a software search is something that we can freely modify. Only once those options have been exhausted according to the project requirements, do we turn to proprietary alternatives.