I'm with Dave on this one. The aft cabins that actually face to the rear are probably among the most desirable on the ships. You'll notice on a lot of lines they build many of their nicest suites in that location. I think whoever you spoke with had a communication error or was simply mis-informed. The balconies there are often larger and some provide a 180 degree view so what ever side you're approaching your ports from and leaving from you have great views and picture oppty's. If you have the chance to grab one at the same cost as other side cabins I'd take it.
The only drawback I can think of is if you have motion issues you will feel more motion at both the (fore or bow) front aand (aft or stern) back of any ship.