salgado18 :
If I have a Windows license, why would I install Linux in the first place?
It's really just a matter of preference. It's the same as "If they have all the exact same PC hardware why would I pay twice the cost of a Windows PC for a PC with MacOS?"
Linux has some things going for it. If someone becomes code savvy enough and decides there's something wrong with the underlying source code they can hack together changes and contribute to the kernel themselves; though the bar for being able to do something like that is extremely high on the knowledge side.
It doesn't need antivirus software, has a ton of different aesthetic choices in desktop managers (elementary OS is gorgeous), and can be rewarding to be able to do some things for yourself in the bash shell.
There's also the point that its future isn't entirely determined by a single conglomerate and there isn't automatic data collection happening in the background that can't be turned off. But that probably shouldn't be a concern to most users though it did concern Valve enough to start investing in linux.