Don't be naive! Botnet can be built from the coin daemon.
The only thing that there is no botnet yet, that your coin doesnt have value.
It will remain so until, the dev (or someone else) doesnt pump the coin.
Better have botnets than large ASIC facilities. Here you could turn on mining at any time to prevent 51% or decentralise the network. In bitcoin you actually could do nothing. But yeah, CPU mining is a real concern here.