Humans have a need for social interaction.
I am playing an absolutely fkn awesome single player RPG game just now. Divinity 2. It came out in 2009, yet I have only just discovered it as the devs/publisher simply must lack the resources of the mega RPG studios who have enough clout and wealth to make sure absolutely everyone gets infected with the hype for their inevitably technically slick, yet mediocre and sterile games such as Skyrim, Mass Effect, Dragon Age, Amalur etc.
Anyways, I am playing this game and absolutely fkn loving it. I am thinking to myself that this game has absolutely everything I would want in an RPG in addition to some very novel gameplay scenarios that work wonders. Because I am getting such a good buzz from the game, I am always wishing that I could somehow share the experiences with my friends, but of course I can't. Furthermore, I can spend around 3-4 hours playing the game at a time. Arguably that is time that could be spent socialising or attending to real relationships. Further still, when I am visiting friends and such, the thought always occurs to me that actually, I am pretty bored and would much rather be at home running and flying around my Divnity 2 fantasy land.
Not only can single player gaming 'feel lonely' due to the human need to share experiences being frustrated, but the almost instantly pleasurable sensations associated with gaming, can also sabotage the process of socialisation itself, whereby you may prefer to sit at home and game other than hang out with a group of guys, who mosre often than not lack the immediately accessible inspiring and stimulating input that a video game offers. Thus gaming not only frustrates a basic human need, but can also distract us from fulfilling this basic need.