In regards to free enterprise has the US lost the ability to channel its inner immigrant? (Details inside)

With Castro gone, a horde of specials, shows talking about what businesses exist, and or thrive under the communist regime. Many businesses seem to press forward even under draconian rules and laws of the Cuban government. Has the US lost that ability be resourceful over extreme obstacles? The average Cuban seem to be overcomers who are demined to thrive in spite of sandbags and roadblocks, why does it seem some (maybe more than a few) Americans fail to try or quit at the first obstacle or difficulty when embarking on an entrepreneurial endeavor?