Advisor: We've sent a probe through the wormhole! It indicates that there are 12 planets on the other side, but the signal bandwidth coming back is so low that we can't tell which are habitable.
Me: What resources do we have available?
Advisor: We figure we can put together 12 landers, each capable of going through the wormhole and then travel to and safely land on a planet. But they won't have enough fuel to return. I figure we can get enough volunteers to put one person and one robot on each ship, with supplies to keep that person alive for a couple years.
Me: So there we'll be sending each person alone, with no companionship except a robot, to a planet that might not even be habitable, with limited supplies and no way back?
Advisor: Yes, it'll probably be a suicide mission, but i'm sure we can find some brave souls to volunteer!
Me: Couldn't we just send the robots without the humans? Without all the weight spent on supplies there might even be enough fuel to return after assessing the planet.
Advisor: Wouldn't work, the robots don't have enough initiative. This mission requires human intuition! Since we can't communicate easily with them once they arrive in the system we need humans to go along with them. And because of that limited bandwidth we won't hear much more back from them than "habitable" or "not habitable", so we need to be very sure they make the right call.
Me: But the problem with communications is just with sending the signal through the wormhole itself, right?
Advisor: That seems to be the case.
Me: So why don't we send the 12 ships with 12 humans and 12 robots. But when they get to the other side how about they stop there. They use telescopes and other sensors to scan the planets from a distance where they can decide which seem most promising based on more detailed data. Then maybe they pick the six most promising planets and send ships there, maybe even just with robots on board while the humans stay behind. Then if the robots confirm the sensor readings a second ship can be sent down with another robot and a couple humans. The 12th ship should stay in station by the wormhole, collecting reports from all the other ships. When it's determined that a habitable planet has been found, or that they've exhausted all their resources without finding anything, that ship can fly back through the wormhole and let us know exactly what's going on, instead of depending on disjointed and possibly faulty low-bandwidth reports.
Advisor: Huh, that would probably work a lot better.
 This excuse (or something very similar) has been given by Nolan in interviews in response to the same question.