The 10k for the masternode are not staking, in fact if they would stake, the masternode would "break", as the 10k collateral would not be intact anymore. You can still stake anything
other than the 10k on the masternode address, but some people like to keep the masternode "clean" and send the rewards to some other address or even a different wallet.
You could have the MN running on a Raspberry PI / a different PC / a cloud service and send the rewards to your local PC. Or you are selling the rewards on an exchange. Or some other use-cases I'm not currently thinking of

Yes, understood.

I have the VPS ready (just waiting to cryptopia for approval...). Would be interesting if wallet could stak on the same server, but no linux version yet I´m afraid, right?
How do you specify another wallet for rewards? When I followed the MN instructions didn´t see a command to specify that.