This seems like a variant on the "Where is everybody?" argument against the existence of extraterrestrials.
Aside from possible environmental incompatibility and the possibility that they are simply too far away anyway, there's no guarantee they'd detect us. We've only been broadcasting for a little over a century. So there's a radio shell with a diameter just over 200 light years across surrounding Earth, and at that distance, who knows if it's even distinguishable from background radiation?
That said, I'm not optimistic about FTL travel being possible. Just this isn't a good argument for that view.
Regarding our radio signals, the thesis I put up suggests that the aliens would have scouted the galaxy and found Earth long before we were even here.
Also, it's my understanding that our broadcasts do fade to nothing before they even reach the nearest star, and the whole SETI project is thus all the less likely to hear alien signals.
King Daniel has a point in that the warp-capable aliens could simply miss the Earth, even over the span of a great galactic empire's existence.