performed throughout the past. Linux players payed the most out of all the other operating systems for the bundle.
Look at what valve is doing: bringing steam to linux. Look at the latest kickstarter: Planetary annihilation that followed up on public demand and is being developped for linux now too.
There's a feeling of change and it would be a shame that Paradox would miss out on that. Better yet: it would be great for them to lead the way.
Plus having a game compatible for linux does not neccessarily exclude windows.