I am a fan of Engineering - it gives me Parachute (slowfall), AoE Taunt dummy with 75k HP (saved me or my party many times in HCs), 480 stat Gloves gizmo on 1min CD, Epic Engi customizable helm, Jeeves (repair bot), Moll-e (remote mailbox), various teleports across the world - and some other fun items! Also guns and bows and crossbows that you can reasonably sell, as well as the gnomish army knife that can rezz fast and without mana cost! And the best fishing lures in the game is made by Engi xD!
Both gizmos i use have NO chance to backfire, and there are even more devices that can be useful - i just have not gotten around to making them
It may not be a "clear cut" profession like JC or BS where your bonuses are quite simple, but with all the stuff i mentioned above - i believe it is more than viable, not to mention it is very very useful and fun!
Only bad side of Engi is that it is nasty for leveling, but once u max it out - hilarity ensues! xD
So, why do so many players hate Engineering?