> Do you think the same of kids going to play soccer with their friends? Why / why not?

Has to do with the social skills that you learn and practice. Gaming is an escape from the real world in a bit of a different way - all social contact is reduced and "giving up" is as easy as a keystroke. The rewards you're getting are intangible and created by a programmer to entice you to make numbers go up or get a new hat, only applicable while you're still playing the game. It can be a wonderful place for people on the low end of the social spectrum to practice working together in a safe environment but rarely have I seen people get better at overcoming social problems that require tenacity through gaming.

I think these are two different things that should be separated. Ranked games with matchmaking and hats/achievements. One can exist without the other and they pull in people for different reasons. For example most of newgrounds has achievements / hats / whatever, but no multiplayer at all. On the other hand hearthstone has ranked games but very little to do with hats (there are paid and collecting elements, but they actually affect your play - they're not useless tokens). Then there's Dota with both.

> "giving up" is as easy as a keystroke

Kids often rage-quit games and interactions in real life games. Not sure if it's that different from this point of view.

Really dota 2 has stuff that you buy with $ that affect the gameplay ?

Badly worded, can't edit now. I meant both the ranked play and the useless tokens/hats.