Equivocating between MWI and inflation, as in your dialogue, is bad.* But asking whether a specific argument is bad is usually a wrong question. I think your dialogue is a confused memory of a coherent argument. Inflation is pretty much accepted and that is definitely evidence for chaotic inflation, although perhaps quite weak evidence. And chaotic inflation is pretty much the right multiverse for the full argument.
* Maybe that is the fault of Tegmark, who calls MWI a multiverse, unlike most people; but, as Viliam notes, he does make some anthropic fine-tuning arguments via MWI and ordinary inflation.
Equivocating between MWI and inflation, as in your dialogue, is bad.* But asking whether a specific argument is bad is usually a wrong question. I think your dialogue is a confused memory of a coherent argument. Inflation is pretty much accepted and that is definitely evidence for chaotic inflation, although perhaps quite weak evidence. And chaotic inflation is pretty much the right multiverse for the full argument.
* Maybe that is the fault of Tegmark, who calls MWI a multiverse, unlike most people; but, as Viliam notes, he does make some anthropic fine-tuning arguments via MWI and ordinary inflation.