The vast majority of crafted goods worth less than the materials used to make them in your statement are perfectly logical econnomically.

They are common recipes, available to everyone who is skilling up the profession. The large number of crafters creates a situation very close to a perfectly competitive market, where people will make zero economic profit. The thing is, the skillup point is worth enough to the crafters to where they'll gladly price at a cash loss because their true payoff is in levelling the profession. With the exception of a couple of weapon enchants and twink enchants, there is nothing in most servers that will turn a profit in enchanting until the high end, where rare drops make the market an oligopoly. This is because the cost of enchanting is nearly always higher than the cost of just buying those better stats on a new piece of gear in the AH for the midlevel range. Once you hit max level and there isn't an abundance of gear upgrades, then the marginal cost of improving your stats shoots up. (See green/blue/purple gem pricing in BC before Brilliant Glass and badges for Epic Gems)