Your work laptop might be sharing a network with everything else you own (provided you work from home sometimes, that is). So, why would you want your work laptop to live on a separate network? Plus, the unpleasantness works both ways: just as your local network is exposed to your work through your laptop, your work laptop can also become vulnerable through your local network and put the company at risk. Connect the work laptop to that Wi-Fi and make it forget your main network so it can't just reconnect later. But that doesn't mean you shouldn't give your work laptop its own VLAN.