Lets take a look at history of the light bulb. Thomas Edison did not invent the light bulb. The light bulb was invented 70 years prior to Edison's light bulb. Over that 70 years many people tried to improve the light bulb to make it viable. It was Edison that finally succeeded. Since his bulb was the first truly commercially viable bulb, and because of its rapid adoption and revolutionary nature, we can think of it as the bitcoin of lighting -- the bit-bulb.
Now, if the author were writing about light bulbs, he would write, "why are people developing alt-bulbs? None will ever be as successful as Edison's bit-bulb." Of course, he would be terribly wrong. Now, after 100 years of trying to improve on the bit-bulb, complete replacement of the bit-bulb by the fluorescent alt-bulb (and followed by the LED alt-bulb) looks imminent.
But nobody is trying to develop a new Bulb.
To stay by your analogy all that is being done is to take the existing light bulb and change the socket in which it fits.
Also the Author says that an altcoin that offers similar advantage over Bitcoin as Bitcoin does over Fiat would have a chance of success. But so far none does or even tries to.
As for using them for experimenting, there is this:
https://en.bitcoin.it/wiki/Hardfork_WishlistSo far no altcoin has even dared to tried one of those, because that could backfire, better to just copy the existing design and only change the "socket". --> Profit!