Brilliant post by Kills_Alone!
While I agree that 343 industries should port the Halo series properly back to PC, I think the petition could be structured better.
The simple fact that the Master Chief Collection is being made available for XBox One means it should be extremely easy to port to PC, as the architectures are now largely identical and Windows has the same basic libraries, Direct3D etc. This means the only real work needed is to make sure that keyboard and mouse are supported properly on all titles, and maybe give us a proper editor again, though I'm not so fussy on that point as while the Forge is a lot less capable, it is also a lot more accessible, even if it still needs a ton of improvements. The main thing is to get the games, and a means of playing them with friends (ideally locally, not enough PC titles support this) and online.
I just can't understand why they wouldn't do this; it'd easily make back the cost of porting the titles and more, and it's not like it's encouraging competitors as it'd still be limited to Windows (so more money for Microsoft). This means it'd never be available to Steam OS machines except by streaming from a Windows computer, or dual booting Windows, either way the user is paying for and using a windows license somewhere into the bargain. While I'd love to see it sold via Steam, Microsoft could just as easily sell it through their own Windows Store. They wouldn't even really need to sell the PC port(s) on disk, as downloads are plenty popular now (in fact it's the main medium for PC games now) so that's another cost avoided.
Otherwise it's just a huge shame; I got into Halo with Halo 3, but now have every title available for the 360, which means I'm still missing Halo 2 which is now skipping the 360 entirely (thanks 343!). But I'm not interested in buying an XBox One purely for Halo 2 anniversary edition and Halo 5 (or at all), so I'm most likely switching back to PC as my main gaming machine (albeit a compact console-like system like the Alienware Alpha). I guess that means I can play Halo 2 at last, but none of the more recent (or future) titles. The huge assortment of other non-Microsoft PC games ought to ease my suffering considerably, but it's the perfect example of lost sales for no reason; hell, I'd be buying a second copy of many of the games, but I wouldn't mind if it meant I could play it on a proper PC, as I'm not going back to a locked-in console ecosystem.