Games are now a rich part of our culture. They can tell great stories, and are not "better" or "worse" then a book per se. If you enjoy them in moderation, and go outside enough, games are a great thing. And LAN parties were a great pastime.
Malware, hacking tools, warez were one gateway for me into serious programming. I downloaded Visual Basic or Visual Studio and proceeded to write a trojan, to make friends' CD tray open and close on LAN parties.
And porn? Grown ups and parents don't like to hear it, but as a teen I of course enjoyed that there was porn on the internet. It didn't hurt me, and I've had healthy, normal relationships in my life.
...and a minute fraction will play on the football field or perform in the school theater.
They'll just use the browser for porn, no need to install third-party software.
Unless you actively try to stimulate the smarter kids and give them something to sink their teeth into, it's extremely difficult to tell the difference between kids who are bored and miserable because the material is below their level and kids who just don't give a shit about learning. In both cases, they'll be goofing off, not paying attention, and possibly disrupting class, but one group can flourish under the right conditions, and the other group is a lost cause.
Without games, there wouldn't have been any point to dig deeper than word processing.
Learning to avoid malware is an important skill for kids to learn. Shielding those kids will just create a bunch of adults that get infected.