I will say 3D printing is "disrupting" a few areas. Take GE's use of printing of aircraft jet nozzles. This is a case where GE has just about phased out many processes to rely upon 3D printing. To make prototypes, GE has spent hundreds of millions of dollars and is certainly evolving the area if not disrupting the disrupting it. GE as a company has invested well over a billion dollars on 3D printing investments.

In many other areas its not so much disrupting as it is evolving. Some automotive companies are gearing up to provide replacement parts by 3D printing, as stocking many parts for many vehicles is very costly. But if you look at 3D printing of prosthetic hands with the e-Nable project (Google It) its quite hard to call this anything but disruptive. Its not replacing something else, but rather creating a BIG solution where none existed.

Things do take time, but give it 10 more yours, and I bet you will see much more proof.