Just to be clear: This isn’t about self-writing code. These are platforms with visual interfaces for non-technical people to develop simple applications. There is still coding going on in the background and, of course, for more complex applications you need someone qualified to write the code.
Nevertheless, for basic apps, you don’t need new code. You just need to put the right pieces in place. There’s no reason that qualified developers need to waste their time with these types of applications, when a fairly intelligent person armed with a simplified, visual programming environment will do.
In any case, these are real companies getting paid real money (and a lot fo it) by other real companies, so I think it’s safe to assume that real value is being created.