Double checking; there aren't any restrictions ahead of time for whom the "Stack Exchange network of websites" are available, are there?
Surely this is just a poor choice of words, and the author has been to busy to notice the up voted comment below the post.
If I'm wrong and SE is not for some people, please enlighten me.
The post goes on to explain the purpose of the site, but I think the idea that some people should be excluded from using SE because of who they are can't be the author's intention, and an adjustment to the language could make this clearer.
The answer goes on to talk about how users interact with the site, and that's certainly a reasonable way to approach the OP's question. So maybe a "Yes, but..." makes better sense than concluding that "SE is not for some people"?
Somewhat related: Is this site for beginners?