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Incorrect. The point is that no matter what proof-of-work algorithm an altcoin employs, those who are protecting Bitcoin will rent enough mining hash rate to fuck your coin forever. They only have to rent it for a short period of time, and your difficulty will be so high that it will never produce a block again. And all the money in the chain will be unspendable for a very, very, very long time.
The "attacker" has the resources to do that to any proof-of-work altcoin which doesn't have the level of hashrate of Bitcoin.
Of course the altcoin can then manually reset the difficulty lower using a fork, but then the attacker can repeat again. It will quickly become clear that the altcoin is fucked.
If Monero starts to approach $1 billion market cap (or perhaps much less if the liquidity is very high, which it is for Monero), this attacker will destroy Monero and profit by shorting.
Dude you need to read tardlema a little longer before reposting the derpage here. (I've been reading for years as you can tell by my fluent orcish).
Otherwise, go ahead and rent some SHA256 asics and attack litecoin and monero with them. I'll wait.