They should be. Now a little bit of explanation here, I used "bump" because that's what Tom and B'Elanna did to pass a ship in the race. Now I'm using ramming which is just a really, really hard bump. True it may be a tactic of last resort, but it is offensive and it works better if you have shields. Also, if I'm the captain of a Galaxy and a Romulan scout ship turned to fire at me and charge me. I'd drop aft shields, transfer that power to the forward shields, and keep running right at them, my weapons firing too, so they can't try to get around to my unshielded behind. Ram my ship right through their stupid pointy eared arrogant selves.
How often has anyone used the shields offensively?
If something that bumps into is considered an offensive weapon, I suppose a bumper car should be declared an WMD.
Excuse me? WTF does that mean? How can you compare the two? In the Trek Universe a starship itself is a WMD by our 2011 standards, not by theirs. Completely false analogy. I'm truly surprised you used it.