Stickin' it to
Bill Gates Steve Balmer Satya Nadella?
Right now I think you have it the wrong way round to decide to go for Linux and
then wonder what good reasons there are to do so, but you should find you have a good platform almost infinitely reconfigurable according to your needs, you can take advantage of a strong community support system that can avoid the problems of a proprietarily-authored 'hermetic' OS, any security issues that exist that you don't get fixed immediately are unlikely to be at the very top of an attacker's list (when they can profit more from trying to exploit anything Windows/its user has not properly patched), code-bloat should be easier to avoid[1] because (relative) experts like going through things like this without the pressures of management-deliverables being priority for maintaining their salaried position...
Disadvantages: 'Mainstream' software may not be written to work off of the MS/Mac/both-if-you're-lucky platform, making it at least a bit awkward, and you get all kinds of things you can do wrong that you've never known you can do wrong before...
Your experience (and list of pros and cons) will probably be different, but the above probably relates most of my experience in the matter.
[1] Though not going into your respective Package Manager and selecting hundreds and hundreds of things that "you think you might want to try, some time", which is always a risk I seem to succumb to on first install of a new system with that philosphy. It takes months to decide I have too many 'gravity/physics-based arcade games', or whatever the whim was I fell for at the time...
ETA: Question of my own for those familiar, after glancing at the Wiki pages on Boot Loaders... Is GRUB and GRUB Legacy essentially GRUB2 and GRUB(1)? Last time I set up anything, GRUB2 was coming in but not yet inbuilt as an option for the distro I was actually setting up, and... you know... there's been no reason to change what works since.