So, let's talk about why Azerite gear is somewhat spec locked... In the last Q&A Ion told about the design philosophy behind the Azerite gear and why it cost an exponentially increased amount of gold to respec/reforge it.
When people compared it to tier gear not being spec locked he said that tier gear was a special case and back then they didn't want people to farm the same piece of gear multiple times which makes sense..
BUT..
We are currently doing the same thing now! We have to farm multiple pieces of the same gear! Blizzard say they DON'T want us to reforge. They DON'T want us to reforge. They gave us the option to do it, but optimally we shouldn't use it.
Their goal is for us to have an Azerite gear piece for every situation. So they want us to fill our bags with Azerite gear which in some cases will be multiple pieces of the exact same armor. So based on their own logic, I don't see the difference between tier gear and azerite gear in relation to being spec locked.
I think their intention of having a gold cost on the reforging is something else. To some extend gold have become equal to IRL money because of the tokens.
PS. don't get me started on what he said about why raid trinkets are being underpowered compared to M+ trinkets. #BlizzLogic2018