Going back to Rick's home town might seen like a good idea, but it remains basically an open area, difficult to defend or keep walkers out of. The prison is potentially more easily defended, or at least could be made so with less effort. The problem is, both places are just too big to be defended by that small a group. They should be using their time of relative, though temporary, shelter at the prison to procure at least a couple of good sized trucks and forage the area for canned food, weapons, fuel, medical supplies, and just about anything else that isn't nailed down that might ever have any possible use.
This isn't some temporary difficulty, where the Power Company is going to restore service in just a few days, or the Postal workers are going to come back off strike next Tuesday. Rick and his little band can't expect help, EVER, and they need to be facing that fact and making plans for the long haul. Right now, all that they're doing is playing scavenger. Eventually, all of the canned food is going to run out, and game is going to be scarce, if not totally nonexistent. They need gardens, livestock, and to basically become a self sustaining unit. And, most importantly, they need NEW MEMBERS. As small a group as they are, no matter how loyal and dedicated, simply can't exist for very long against the kind of predators, living and zombie, that they have already encountered, let alone the roving gangs that almost certainly would exist in a situation like that.
