It's part personal preferance since a big part of male gamers find guns, realism and technology appealing, and not only that but these games are very straight forward so any one could follow it.
I also found out from my brother and his friends that they are also popular for being popular, meaning they like being part of the crowd. Plus, the RPG elements can be very addicting to most. Aiming for upgrades can be my main motivation sometimes in a game, so it can be what keeps people hooked over games with no upgrades like Counter-Strike.
Also, I do believe there are advertising strategy's involved to attract a young audience besides putting up banners bloody everywhere.
I also found out from my brother and his friends that they are also popular for being popular, meaning they like being part of the crowd. Plus, the RPG elements can be very addicting to most. Aiming for upgrades can be my main motivation sometimes in a game, so it can be what keeps people hooked over games with no upgrades like Counter-Strike.
Also, I do believe there are advertising strategy's involved to attract a young audience besides putting up banners bloody everywhere.