Will you though? What's the cost of the extra development and maintenance you'll need to do to cater for such a tiny sliver of the population, many of whom will just whitelist your site if they're interested in your content?

Around 1% of users run linux. If you have a commercial videogame, you will lose money and users if you don't think about this.

Now consider the ROI. I'm a full time linux user myself, and still I understand when someone says 'sorry but such a small market share is not worth bothering with.'