Creative Interpretation

I was sitting in a Lutheran service at college, when I heard a familiar story being told. For those of you who aren't familiar with the healing of the ten lepers, here is how it goes:

Ten lepers approached Jesus one day, begging for them to be made clean. Back in Jesus' day, lepers were thought to be horribly contagious (insofar as people at the time knew what contagion was, but theoretically, if you touched a leper, you got nasty horrible things happening to you), which is now known to be untrue, but as such they were treated as outcasts. If they could be cleaned, and prove themselves to be clean, then they would be allowed to participate in society. Jesus healed all ten, telling them to go to any of the local priests and show themselves to said priest and ask him to verify their being healed and clean. The ten men departed and did so, and found themselves to be exactly that -- except the one man who, being healed, immediately turned around and found Jesus to thank Him even before seeing the priest.

One man came back to thank Jesus, and Jesus wondered out loud where the other nine were. Still, He told the man to go and be well, as he is now healed.

End of story.

It's a funny fact, then, that this is not the end of the story according to the church I'm from.

The version of the story I heard is identical, except that there is another section at the end that is not actually in the Bible at all. I didn't know this until a long time later, because I hadn't closely read the story, but it turns out that my old church amended the tale. In their version, the ten lepers depart, one turns around and thanks Jesus, and Jesus sends him on his way again, wondering where the nine are...and after that, the nine find themselves to be lepers once more, because they didn't say thank you. Essentially, Jesus curses them for their lack of gratitude, which is never something we see Jesus doing at all (ever -- the only thing He ever curses is a fig tree, which he withers as a demonstrative gesture accompanying something He said).

What does this mean, then, that some conservative churches feel the need to turn Jesus into some kind of punishing figure, even when the evidence they want is something they had to create themselves? That Jesus isn't a merciful healer, but instead some sort of divine overseer, rewarding the good but exactly strict justice the moment any mistake is made?