I agree. I would like to seem more details of how they determined it was only crypto mining. Finding only mining scripts in your logs doesn't mean they were not running other code once they had root.
It seems bizarre to me that a crypto miner got in. It wouldn't make much money on regular CPUs, and the high processor usage would immediately draw attention. So it looks like a low-effort botnet, which is embarrassing to get pwned by.
(The coin mining could be a cover like you mention, but it seems unlikely since it naturally draws attention.)
(The coin mining could be a cover like you mention, but it seems unlikely since it naturally draws attention.)