Last time I checked, there's no power outlets in the woods. That right there eliminates the potential to use an electric motor for most uses on a woodsplitter. In a situation where it can be installed at a source of power and stay there, fly at it. The reason a 5hp electric motor will outdo a 5 hp gas motor has only to do with the fact that a 5hp electric, delivers that all the time, the gas only delivers that at peak output.
Mechanically speaking, an electric motor is simpler, but practically speaking, it is a PITA if you plan to use it anywhere that doesn't have a ready access to an electrical outlet. I see no point in dragging a generator to the woods to power a splitter with an electric motor, if I could have simply used a gas motor in the first place. All that is doing is dragging more stuff around to accomplish the same thing.
If you'll go back and reread the post you quoted, nowhere did I say a 5hp gas motor would outrun a 5hp electric as you seem to have come up with. I said that unless it was a specific use where the power source was available, that it would limit where he could use it which would be a PITA. Electric motors are great, where you can supply them with power without resorting to excess lengths of extension cords, or dragging a generator or batteries around. Where portability is an issue, as in the ability to split wood wherever you want to, gas motors have the edge.