You could be right, but it's interesting to note that Linux took off because it was actually trying not to be too ambitious. I can't find it now, but I think Linus's original email announcing it said something along the lines of it just being a toy project for experimentation, and not a "proper" OS like the one GNU is building. As you're probably aware, the kernel of the GNU OS, Hurd, involved am ambitious microkernel design, and now 30 years into its development it's still not usable.