Well, if you check out the steel ingot prices from 10 days before, you can see that the price fluctuates, a LOT.. But even at that low price, it's still mostly profit.
As far as why anybody needs those HQ items, I have no idea.. I just know that if I sit on it long enough, it will sell.

Thing with horn glues is.. I seem to have a monopoly on them now, I didn't force anybody out, but I guess the thought of earning a profit of 2-3k each craft (25 sec) doesn't appeal to anybody else. But that's still ~300k/hr in profit.

It's certainly not the most time efficient method to make gil, but all the crafting can be done semi-afk with macros which is what I do with a dual monitor and playing another game at the same time.. I can churn out a decent chunk of stuff to sell.