You know what? You're the only one here thinking that this encounter is meant to end in a tpk. Which tells a lot about the kind of person you are.

Your comparison is simply stupid. Deal with it. You don't understand the point I'm making and you're crying like an entitled player would if he couldn't do anything he like at the expense of everyone else. What am I supposed to tell you? You're defending a spoiled kid making a mess here and using dumb comparisons to make your point.

This encounter can serve as a narrative tool to put the campaign back on track. It gives the characters an opportunity to change. If you can only see that as a punishment you have the maturity of a child.