Bullshit that web 3d won't be adopted. It already is! Google maps uses web 3d pretty heavily already, and it's a perfect example of this.
But even if i concede that point, i still don't agree. Who are you to say that this doesn't solve any problems?
Say for example a website that wants to include something so you can view a product in 3d and be able to move it around and inspect it.
That's not something i want to have to download a full desktop program for and give it access to god knows what on my machine for, but it's something i'd love to have to see a 3d render of something to get an idea for it's size/shape/other features.
OP isn't even marketing it as a library for "games or other 3D-heavy applications", he's marketing it as a really easy way to get some 3D rendering in the browser.