the hashrate is too tiny
It was big enough to mine two blocks with BTC's difficulty. Adjusting the difficulty, like BCH did, is doable, and can be done quite fast. Of course, they are free to brainstorm, and sit on a halted chain instead. If they would really think it through, then it could be even a soft-fork, if they will implement fractional confirmations, and weak blocks properly. And also, going back to BTC is always possible, but well, they wanted to fork, so they did.
this altcoin is extremely susceptible to 51% attacks
As well as BCH, BSV, and a lot of other altcoins, which use the same algorithm. But well, at least they can process any transactions.
the attacks would begin since there would be incentive to do it by then
They basically created a warnet by claiming, that spam can be stopped. A lot of people would show them, that information is easy to spread, and hard to stifle, and it will be just a challenge in itself, to demonstrate, that data can be always pushed, no matter how hard they will try to block it. Ironically, now their chain is fully resistant to the spam, because all of it is filtered by Proof of Work. Unlocking it will just make attacking possible again.
