When our oldest was younger - he is nearly 14 now - say between 6 and 11 years - he hiked with me on most trips. Since it ws just him I never had an issue with him bringing his Nintendo along. It was only for camp, only after dark (or if it was too cold or buggy to be outside). It gave him something to relax with and fun.
Not everyone agrees with my method....but hey he hiked adult miles and did my trips so I figured he could have fun.

It is different if you have lots of kids along though....but teens are a different lot. If they like video games and have a system don't necessarily say no - just have ground rules on them.