2 in the inner and 1 in the outer (Eruvin 65b)

The gemara quotes a case of a Jew and a non-Jew living in the inner courtyard and only a Jew in the outer chatzeir. The gemara concludes that they can't carry in the outer courtyard because it's two Jews since the people from the inner walk through there but they can carry in the inner courtyard because there it's only one Jew living with the non-Jew and nobody else comes through. The gemara says this is based on R' Eliezer Ben Yaakov's opinion. Later the gemara says that they made the gezeira in this case even though it's just one Jew living with a non-Jew in a chatzeir because in this scenario it's not uncommon. The Jew isn't afraid to live with the non-Jew in the back because the guy in the front will check up on him if he doesn't come out for a few days so the goy will be afraid to do anything to him.

Someone asked this morning if that's true then why can the Jew in the inner courtyard carry? It's common for a Jew to live like this so they should have made the gezeira in that case! I immediately responded that it's true that in that scenario it may be common but they just made the rule across the board that one Jew living with one non-Jew in a chatzeir isn't a problem so they weren't going to pick out common scenarios and forbid only those. It's just an across the board rule.

I saw though that the Ritva asks this exact question. He answers that it's the fault of the guy in the outer courtyard that the inner guy is willing to live there so he's the one who gets penalized. If it wouldn't be for him the guy in the inside would never live there. He then asks the obvious question that we should just penalize both of them. Maybe I could understand choosing the guy in front if we were forced to penalize only one but we can easily penalize both. So he answers that we don't penalize the guy in back so as not to differentiate in REB"Y's opinion (which is basically what I said - baruch she'kivanti).