Obviously as an anecdote, I can’t say how prevalent these types of issues are among homeschooling in general, but I do believe it’s enough of an issue to be concerned.
We already have enough people raised who have trouble understanding issues that are of vital importance to our society, and it’s only becoming more of an issue. In a democracy we need an educated electorate who can make some basic educated decisions when voting.
Public schools are not perfect by any means, but at least we have some say as a public about those curriculum, and have successfully fought things like intelligent design being taught in schools. A growing homeschooling trend takes those issues further out of the public’s control, and it’s in the public’s interest that kids all get at least some basic level of education.
We need to take steps to strengthen our public education system, and the trend of homeschooling is at the very least an extremely concerning indication that our public school system is failing. It’s a national crisis, and most certainly will affect the US ability to compete against countries like China with strong public schooling. (Studies consistently show that Chinese students beat American children in all academic categories.)