If you count things like Weebly, the answer is: a "whole bunch of people", heading rapidly toward "everyone". Not that long ago, every Weebly customer would have meant a programming job for someone. That kind of work is gone.

Then take a close look at AWS, Heroku, Rackspace...those were all systems engineering jobs. Startups don't have to hire people to do that now. What used to be thousands of jobs is now maybe a tenth of that.

"the average guy with an MBA definitely can't throw a MVP together"

You're wrong. It happens all the time. It happens so often that's a cliche. You can't go to a meetup in the valley without being assaulted by ten brohans looking for "feedback" on their "MVP".

The important thing to realize is that the need for software engineers doesn't scale with the maximum complexity of software projects; it scales as a function of the average complexity: think of a bell curve, where the X-axis is "complexity", and "need for engineers" is the area under the curve to one side of some vertical line. We keep moving that line further and further toward greater complexity. So far, the distribution has shifted to keep up, but there's no guarantee that will keep happening.

Are we going to need people to write complex, novel software in 2050? Absolutely. Will we need more people than we need to write complex, novel software today? That's not a question with a predictable answer. It might well turn out that the "average" programmer (say, the ones who know how to use Rails and jQuery and are fond of complaining about interview questions involving algorithms) is a doomed creature.