I find the player economy of Legion to be rather messed up. It isn't as if you couldn't craft useful items; but everything is so damned expensive that few people buy or bother with crafting and selling. A flask that gives you a 2-hour stat bonus on my server costs 3000 gold, and very few people other than high-end raiders spend that sort of money for a short term buff. And the high price isn't a profit margin of the crafters, but comes nearly exclusively from the high price of the gathered raw materials like herbs and ores.

The culprit probably is the previous expansion, where the garrison gave everybody herbs and ores without needing the skill, so many people unlearned their gathering professions. And although you can gather in Legion with low skill, apparently not many people switched back. Maybe because skill isn't the determining factor any more, you need to do a lot of gathering to find quest items that give you quests that increase your gathering skills. Without those every node only yields little. Thus you can find basic ores or herbs going for 50 to over 100 gold for a single one. Stacks of 200 ores or herbs cost more than BoE epics.

Another reason why few people bother with crafting is that there are other alternatives. You can get a set of class armor and upgrade it to high iLevel using order resources. And if you do a lot of world quests, you'll also find a lot of good gear. I just recently discovered that you can buy bonus roll loot items that work on the weekly purple world bosses, giving you a chance of an iLevel 860 item without ever needing to enter a dungeon.

My warrior has mining and smithing, my mage has herbalism and alchemy, and my priest has tailoring and jewelcrafting. I haven't found any great money makers yet in these professions. Some people said stirrups would sell, but I found few buyers that would pay more than the cost of the materials for those on my server. And unless gathered materials become a lot cheaper, I don't see myself crafting flasks or turning crafted items into obliterum.