I see teenagers drinking energy drinks and I'm always thinking marketing really works on teenagers. Because those are the only people drinking that shit and they are also trying to appear "cool". So easy targets for marketing.
In the US, that's actually because of semi-voluntary regulations. In the EU and other areas, it's less voluntary.
They can't claim or imply that drinking will help improve your social status or sexual success. They also can't claim or imply that it'll help you relax or that the alcohol is a positive quality.
Basically, they're not allowed to show someone drinking and looking like they're having a good time... But they're allowed to show one or the other.
I prefer a sugar free red bull to wake up first thing in the morning instead of coffee and I haven't been a teenager for over a decade. It works better for me and tastes better. Its all just preference.