Testing new software in a VM is done primarily because (as stated above) you "avoid polluting your current system". When you are done or if anything goes wrong

Testing new software in a VM is done primarily because (as stated above) you "avoid polluting your current system". When you are done or if anything goes wrong you can just trash the VM. This is standard practice in a variety of situations and has other benefits. The only twist here is the software you are testing happens to be virtualization management software. Make sense?