Price. A gaming PC cost 5 to 10 times as much as an XBox, and I don't care about high-end graphics. My laptop, while very new, is limited by its built-in low-end graphics card that I can't replace. It chugs on Team Fortress 2.
Not caring about high end graphics is fine and that is preference anyway. I play console a lot and I think it is good enough for most games, just not large open world games and almost all RPGs. Having said this, you made a blanket statement on cost while not listing the advantages of PC gaming. Firstly, the cost of most games on most PC games are $10 cheaper, and your cost factor is way overboard, unless you bought your own TV for use with the console, you have to share the TV:
Advantage to PC gaming:
One can mod the games.
Load times.
One can move/copy their saves and setting files for back-up, just in case.
Not forced to take updates/can remove updates and still play.
And an intangible; the modding/PC tech community nearly always has fixes and tips for issues well before the console versions, due to Sony's and MS' certification processes.
As far as cost, you can get a good rig with a nice monitor, nice sound card, speakers and powerful graphics card for around $1200.
By a console, a decent TV big enough to sit far away from to view, and you've gotten close to $800-&1000 right there. That's excluding the WiFi addons, surround sound and extra controllers and the HDMI connectors.
In the end, the cost of PC gaming doesn't factor as much as it did years ago when a good rig would run around $2000+
The one HUGE advantage I will give to consoles though, is the ability to sell the games. If one has a Steam only game (and now Origin based with EA), PC gamers cannot re-sell their games as the key code (typically known as the "Product Key") is tied to their accounts.