I don't like it, but it's true. As Raleigh grows and grows (I mean, it's bigger than Pittsburgh, Buffalo and Cincinnati) I think it deserves to be regarded synonymously with the metro area. But the area being what it is, I don't imagine Fuquay-Varina and Wake Forest natives telling out-of-towners that they're from "Raleigh," and I think we've got decades to go until folks from the Triangle's other two thirds start calling "Raleigh" home.
Transplants are a different story. If I were from Detroit and moved from got a job at RTP and moved to Morrisville, I'd probably tell my Detroit friends I was going to Raleigh.