I got turned on to EGD my junior year when Wayne Hunt was a guest speaker at our college and have been working in the EGD/wayfinding field since. He showed us his projects with Disney and the World Cup Graphics and I was intrigued with the combination of 2D and 3D in this discipline
You are right signage has a -ve connotation to it…but I think it really is just a small solution/subset of a bigger discipline of Wayfinding(EGD, information design, place making etc…)
Aside from the design aspect, the rewarding part about Wayfinding is the analysis and the programming of your content that helps to deliver the right amount of information. at the right time, at the right place to your audience so they can engage your environment effectively. Though most in this field will tell you that no great piece of Wayfinding strategy can effectively solve the problems arising from poor planning by egotistical architects.
As for jobs in the EGD/Wayfinding field try these (and there are TONS in LA including architecture firms with EG studios):