Martin forgot to mention money as being the most important limitation on software. Some customers just don't have the budget to let you deliver good software or to evolve an architecture so that's its cheaper and easier to extend.
..or if we take serious the "social construct" thing then it'll be limited by all the vices and pitfalls of human nature, ain't gonna get far in that swamp of narcissism, arrogance, ignorance and bad listening.