I remember reading a paper a long time ago about traffic engineering. It turns out that when there's a traffic problem you have three choices more or less:

1) Add something

2) Change something

3) Remove something

The paper talked about how most civil engineers have a strong bias toward 1, followed by 2, and then rarely 3. The first thought is almost always to add something. Something is wrong? That means we need something more to solve it, right?

Complexity is not a virtue. It's actually a vice and a liability. It is better to solve a problem by removing something than by adding something. This (along with losing sight of what customers want) is the problem with engineer-driven design. Engineers like to add stuff, not remove stuff.

Wave always looked horridly over-complex to me. The protocol was a tower of babel. It was "open," but it was so complex that nobody would bother climbing its learning curve. It tried to solve too many problems at once, it was slow, and it was cumbersome to use. Those are all signs of over-engineering.