Its not that much superior as you might think it is, but I guess its still too early for you to see that. Lemme guess, you got recent free copy of ED, went to first CG and because you saw more FDL's than other ships, and got ganked by them? So you came to forums, and start demand to nerf FDL because of it? Its like asking why your newb level 1 char cant beat other level 99 end-game char in any mmo.
And FDL is really poor at anything other than a combat. So why FDL should be weak at it? Its end-game PVP ship once at full G5, whenever you like it or not.
FAS, Cheftain, Kraits, Mamba with certain bulids can be equal or sometimes better than a FDL. Its all down to what bulids are used and by how well are being used.
So pls gitgud, dont be so discouraged, go enginneer your ship, and instead of whining about how unfair PVP is, better is to actually learn and adapt. Tons of "gankers" will probly accept friend request if you send them after being killed once or twice by them, not all, but some of them will do.