Relying on things added to the game in previous expansions to make a profession viable sadly do not really help make the profession fun or interesting. Now, we could go into a whole "what is the spirit of the profession" debate, but I think I'll explore it from a slightly less subjective standpoint. With every new raiding patch, blacksmiths, tailors, and so on get multiple items to craft and sell. Engineers, at best, get new ranged weapons to make (which come MoP will only be usable by a single class, as you'll recall) and maybe a scope, both of which have material costs that usually exceed their AH price, as I stated. You may say "well, crafting and selling aren't really what engineering is for. It's supposed to be about fun items!" And yet I cannot help but notice that, with every new raid patch, Engineers don't usually get many "fun items" to add to their list. When they do, they're either severely limited by restrictions, have a more than negligible chance to leave you horribly maimed, or both.