I have made plenty of money by amorsmithing. One I got to around 125 I can buy the materials for around 27 silver per item. I can then sell the item back on the trading post for a price around 40-55 silver. They would typically sell within a couple of minutes on posting on the trading post. This isn’t bad because I can spend only about five minutes in Lion’s Arch making the items and posting them. I go questing for a bit, come back, and have a gold or two waiting for me. I’ve made a lot more if I sit there for an hour doing it.
With that said, this was last week. There are a lot more players who have leveled up their armorsmithing and increasing the supply, thus lowering the profit margin. In Blackgate I can still make about 10-15 silver profit per item, which is obviously a bit lower than what is was last week. However, you can still turn a profit. Is it more than what you’d get doing other things? Your server’s economy will determine that.