Assuming you have the workload on an existing computer, how much memory is it using now?
Personally and professionally I would not run vm's on a gaming system.
I guess it depends on the reason for running the VM. If it's to play with another OS, for instance experiment with a Linux VM on a Windows host, I see no problem with it. Likewise for an occasional thing, like where I have to run a Windows VM (ugh) on my laptop a couple times a year, no big deal.
Anything intensive, frequent, or production mode, agree completely.
Lets be real. 8GB for a working machine, 16GB for a gaming machine, 32GB or greater for a professional workstation or virtualization, etc
I watch my memory consumption while I play. No matter the title, never gets anywhere near 16GB. Just facts and numbers for me.