it is, if the original goal was to be something else.
If you start a marathon and stop to eat the greatest hot dog ever made, it wouldn't be considered a successful run, although you can say "but it was the best!" and be happy about it.
Payment channels aren't in the white paper but they were in the first public release and had dedicated opcodes. That first implementation wasn't very practical nor was it secure.
The fact that modern payment channels are implemented with other opcodes may be a pivot in implementation but not in concept.
Bitcoin was supposed to be much more than it currently is, and the "success" of it is a product of continuous goalpost shifting.
There's nothing wrong, though, with someone taking the open source code and creating LightningCoin from it, though. That would be the equivalent of a pivot.
[0] http://satoshinakamoto.me/2008/11/02/re-bitcoin-p2p-e-cash-p...
Many of the cryptos that claim to scale to thousands of tps on layer 1 are all sacrificing decentralization to achieve it, at which point, I might as well use Paypal/Visa. There's no point in being able to scale to those levels in theory if in practice no one uses them.