Production professions were not designed to be money makers. They were designed to allow players to enhance their characters. Leatherworking, tailoring and smithing allow you to make your own armor. Alchemy allows you to keep your character supplied with healing, manna and buff potions. Engineering allows you to make fun and sometimes useful items that you wouldn’t have access to any other way. I’m not saying that you can’t make money from production professions, but that was not what they were designed for. And like any other MMORPG I’ve ever played, resources are always more profitable than finished products. Again, there are exceptions but that’s generally the case.
So if you enjoy making things have fun with the production professions. If you only want money then take up the two gathering professions you like best.