No, I don't really think so. Reaper-Racing didn't really make a very useful reply, but I don't think I'd describe an amplifier as a "hi-tech powered splitter".
A true splitter takes a single source input and divides it into two or more identical outputs. That's not how I'd describe the most common use for a 2-channel or 4-channel amplifier. A 2-channel amp usually drives two speakers, true; but it almost always uses two separate inputs. There's a left and right input with different audio signals, and a left and right output that each reproduce the corresponding input signal, with more power.
The same is true for a 4-channel amp. If you want to have balance and fader controls through the head unit, you'll need to have four different outputs at the head unit connected to four different inputs at the amp. It's true that in most cases the front and rear audio signals are identical, but they have to be separated if you want to be able to make one louder and one softer. Also, there are cases where the the front and rear audio signals are different (with a surround-sound processor, for example). In this case the amp would have four different input signals, amplified and sent to four different outputs.
In fact, if you're using a 2-channel amp in bridged mode for a subwoofer, it acts as a signal combiner, not a splitter. It takes the separate left and right input signals and combines them both into a single channel for the subwooofer.
So, in my opinion, the description of an amplifier as a "splitter" doesn't hold up in most cases.
Edit: sorry, I still don't agree. I think you may be confusing an amplifier with a crossover. An amplifier usually doesn't split anything. A 2-channel amplifier takes two inputs and provides two amplified outputs. A 4-channel amp takes four inputs and provides four amplified outputs. If you want to take a single audio signal and get two outputs from the amp, you usually have to use a real splitter, in-line between the source unit and the amplifier's inputs.
The normal use of a typical amplifier does NOT include splitting a single input into multiple outputs. So it can't be described as a splitter, even to a novice.