Full plate is roughly the same that it always has been in terms of gp/xp,
As stated, yup. Its about the same in gold, just four times the materials.
I've got similar experience to you it seems, I've done every profession at least twice on my own effort for every profession, and sat though tutoring and assisted crafting for nearly two dozen other characters on various occasions. (I'd be so bold to say I probably have more time wasted looking at crafted animations than my highest steam game at 500+ hours, thats only ~225000 crafting animations!)
I like there being a little depth to professions, but I see these sort of changes as limiting 'other' people, not necessarily myself. I don't care too much, I know how to do it, and I'm still going to be one to do it. I felt like the changes of herbalism did less to balancing the profession's power, and merely limited the availability to the same people who were probably going to grind herbs for the big stuff, It just takes a little longer for them, again.
Same with smithing. I'm still going to be able to make the better stuff eventually. I'm just going to end up with four times as many armors and take longer for the last. I certainly don't envy the person who wants to come around and start from scratch on smithing, or leatherworking.