Minor heresy: "Because that's where the money is" is a perfectly valid reason to study programming or seek a job in software. We're capitalists, right? That's how the market signals "Hey, pardon me, hate to interrupt y'all while you're doings you like, but I NEED WEB APPS."
Yes, the world urgently needs more web apps. They are an extremely highly-leveraged use of a smart person's time. There is no terminal value which you have which cannot be advanced perceptibly by writing the right web app. The world doesn't need *every* web app, vacuously.