Yeah, minimum wage for non-tipping jobs is $7.25 where I live, and somewhere around $2 for jobs that rely on tips. Since a 10 - 20% tip is the norm, a server only needs to serve maybe $40 of food every hour to hit that minimum wage. For the sake of reference, most meals are around $6 on the cheap end, and $10 - $15 is common at a nicer-but-affordable place.

So, yeah, it's low, but as long as the server is doing a decent job, people will tip, and at a decent restaurant, they can actually do better than the (honestly pretty low) normal minimum wage.