Capitalism is a dog eat dog world where the best products survive. Propping up poor products by artificial means just because the producer would go bust is wrong because the producer that creates a poor product deserves to go bust.
You've just described exactly why a Monopoly isn't capitalism. Because Monopolies can prop up poor products by artificial means, by abusing their monopoly in one market to gain advantages in another.
So in essence, you agree with me.