As I said, the Sino-Soviet split was a tragedy. The world would have been better off had it never happened. However, China is not capitalist, just like public ownership under capitalism is not socialism, private ownership under socialism is not capitalism.
Further, I am not giving Mao all of the credit. Of course the USSR assisted. However, you're giving Mao practically none of the credit for overseeing the same tumultuous period Stalin oversaw, in a country even less developed. Mao's economic construction was not a mistake, it was uneven and unstable but ultimately positive, and serves as the bedrock for the modern socialist market economy.
Neither Mao nor Stalin were perfect. Both made mistakes, as any socialist leader will, especially in some of the earliest attempts. However, both also achieved tremendous results.