Grand Theft Auto games are usually best on the personal computer platform. Aside from aiming with a mouse and beating hookers with a mouse and selling drugs with a mouse, the PC also allows for a wide range of modding to Liberty City and it's brethren.
All we can say is that whenever it is viable (technically, developmentally, and business-wise) for us to release a game for PC (or any other particular platform) - we will and we usually do; unfortunately, that is just not the case 100% of the time for all platforms.
To help soften the blow, the blog post continues:
I guess there's still a reason to own a console. In case you were wondering, Red Dead Redemption is f***ing fantastic.