Swift isn't going to make it so "anybody can write apps." That is something that's been tried for decades, with things like drag-and-drop programming. SQL was originally intended for non-programmers. It doesn't work, because the difficulty of programming isn't the syntax. The difficulty of programming is logic.
While true, the danger exists that making the syntax easier will encourage more people who don't understand logic to try to write code anyway, usually with disastrous results. Maybe it's the UNIX greybeard in me, but I've always seen the complexity of language as sort of a "you must be this tall to ride" bar, limiting the amount of damage that clueless people can cause.
And it isn't just that the software that new programmers create is usually bad. It also clogs the marketplace with low-quality apps. The more bad apps people write, the harder it will be for well-written new apps to gain footing, because they'll start out with several times as many poorly written apps ahead of them in their sales ranking.
But the biggest problem with making it easier to write code is that every step down that path requires ever-increasing resources. Right now, it takes about an order of magnitude more effort to write a beginning programming guide than to write a programming guide for experienced programmers, even for a moderately complex technology. And that's if you assume that people understand basic logic, control flow, etc. If you go one step beyond that and try to make it practical for non-programmers to write code, you'll spend two or three years writing a good, solid introductory textbook. And I have yet to see any evidence suggesting that any significant percentage of those folks will be able to write decent code even after reading such a book.
The kernel is stable not just because it has to be, but also because it scares people away until they are reasonably competent at programming. The web is filled with bad code because it doesn't. IMO, apps should be more like the former than the latter. Just my $0.02.