I'll be glad if you don't make me take the time to do it, but I could argue that many, many more companies have built businesses on Linux than on BSD. A huge number of products are built on Linux now. Linux is a more popular embedded BSP OS than BSD is.
Sure, in the case of Linux vs. FreeBSD, you're probably right (although there are certainly more factors involved than just licensing).
My point is that requiring code to be given back doesn't necessarily yield a healthier ecosystem, or even more code contributions, than a more laissez-faire attitude.
