I think the argument was for limited power that you can apply on top of your unlimited muscle power, regardless of speed. I don't see why it has to be so controversial. 250W is a big boost for those who can't go fast on their own; for those who can, it's a convenient and enjoyable but relatively small boost because they can already put down hundreds of watts and increased drag (which is where most of your energy goes on flat terrain at speeds over 20kph) means massively dimnishing returns.

I really don't understand why it is so controversial.