why do guys do this all the time? (not targeted or maybe it is)

Why is having a partner so hard, not saying that like having a bf or anything is too hard in life that i want to break up with them. its just why do they rarely not care. like wdym we were talking for a full 10 minutes and now ur hanging up on me to go play with you're little other friends when we could've been playing together. and why do guys think that the game is so much more important then they're partner. i have a friend named leah and she had this bf which is her ex now, and he treated her so bad i felt her so i had to step in and be the bf. like why are you playing call of duty for 5 hours while your own girlfriend is trying to talk to you and just having a good day, but when you dont talk/play with her back and then she gets upset why do you feel the need to get upset and not talk to her ON PURPOSE.

but anyway, not all guys are like this but why are SOME guys like this?