He's right in the sense that an FPGA will use more power than a dedicated chip. The logic elements are fairly large when compared to the ones in an Intel CPU for example. FPGAs are good for when you know you will need to change a design on the regular like prototyping or when the design will have many updates. If you need it to be faster or you need more than a few hundred, going with an MPGA (depending on the use) might be cheaper. These don't allow change to the design as its baked into the chip but they use the same type of logic as FPGAs and require less power as the logic elements are smaller.
