We still have platform exclusives (sadly), but it's unusual for the platform to be PC. So when Firaxis announced that XCOM 2 would be PC only, more than a few questioning eyebrows were raised. Once you hear why the developer made the decision however, it makes complete sense.
In an interview with IGN's Dan Stapleton, creative director Jake Solomon cites the studio's "expertise" with the PC and its "ambitious goals" for XCOM 2 as its main reasons for sticking with the platform:
On [Solomon's] must-have list were high-fidelity characters and environments, better-looking destruction, physically based rendering, and the crown jewel he'd wanted to get into Enemy Unknown but couldn't: procedurally generated maps. "To do that, we had to use all of our studio expertise ... and our expertise here is PC. That's our home, and that's where we're really comfortable."
I think we can all agree the last thing we'd want is for Firaxis to spread itself too thin and pump out a multi-platform disappointment. After the lukewarm receptions for Civilization: Beyond Earth and Sid Meier's Starships, you can understand why the developer wants to get it right with XCOM 2.
That said, Solomon doesn't rule out an eventual release on consoles, with the Xbox One and PS4 the most likely candidates as they have the hardware for it, but right now it's something Firaxis is "not even discussing yet".