What a specious comment.
In 52 years they have not been able to further and export their revolution due to it and have not been able to be influential as they could have been.
Just think what sort of things they could have done in the 60’s and 70’s if they had been awash in US money.
I have yet to see a good explanation for why having diplomatic relations with China (and by the late 80’s, free trade agreements) is perfectly acceptable while doing the same with Cuba is unacceptable. Nor do I see why if such agreements and relations lead China in the direction of capitalism why they wouldn’t do the same for Cuba.