The implication of that article, that immigrants > natives is wrong and is fuel for the altright sentiment.
That immigrant founders tend to be amazing people statistically makes a lot of sense. The US government doesn't just hand out visas. They go to highly educated, successful people. So when comparing the highest achievers from another country with the average achievers from our own country, of course immigrants look good. Comparing our highest achievers with highest achievers from abroad would yield a more even comparison.
There are of course also seasonal worker visas and such, but those immigrants are not the ones founding companies (nor stealing jobs unless you want to break your back in a field all day).
We should also make it easier for people to take risks (one of the most common attributes of successful entrepreneurs is that they came from upper-middle/upper class backgrounds) by providing a better safety net for those that want to venture out on their own. Socialized healthcare, investing more in education so citizens aren't mired in debt, etc are ways to do that.
I would venture that at least half of successful entrepreneurs are not special or exceptionally brilliant, but they are intelligent- enough, well-off enough to take "risks" over and over, and connected-enough to get others to help with those plans.
We have a massive pool of Americans that could do a hell of a lot more for the country if everyone were given the same opportunity that the top 10% get.