In a space absolutely filled with hucksters and scam artists, vitalik is legit. Good read.
Ethereum itself was the original sin in this respect. In Bitcoin, for the most part, the economic value at stake in a block is (1) the block reward, (2) the transaction fees, and (3) the amount transacted. (1) + (2) + (3) is therefore the maximum amount that can theoretically be "moved" if a block is invalidated through an adversarial fork, since someone else can claim the miner rewards and every transaction could possibly be double-spent. Anyone who wants to be assured of transaction immutability can, at the very least, calculate the total value that is at stake and wait until at least this much PoW has been layered on top of the transaction.
Not so with smart contracts. A paper I read yesterday showed how smart contracts can be used to execute trustless, crowd-sourced DoS attacks on rival blockchains (https://eprint.iacr.org/2019/775.pdf). It's ridiculous. Once you open the Pandora's Box of smart contracts, you can throw your consensus guarantees out the window.
And that's a good thing. We needed an established way to attack rival blockchains that use the same PoW mechanism. They are insecure by design of PoW, and until they are all torn down by attacks, unsuspecting people can loose a lot of money.
What? Nothing could be more unfair. His articles on zk-snarks and starks are probably the most approachable explanations available.
https://medium.com/@VitalikButerin/quadratic-arithmetic-prog...
During the 2016-2017 bubble he was even tweeting that the crypto space had done very little to even deserve the runup. However you had several other prominent people tweeting things that only amplified the bubble, so it did little to tame things, but at least he wasn't participating in it.
If he's a scammer, as you put it, he's doing a very poor job of that.
I don't know much about the details of this particular attempt , but the strategy is not ridiculous on its face. Very implausible, yes, but it contradicts no theorem nor any established law of physics. Mostly, it's implausible because many people have tried very hard to find efficient classical simulations of quantum computers and all have failed.