It sounds like M1 was the nail in the coffin - though you'd think this is a normal question for an investor to ask re defensibility when deciding to invest in the company (a version of the classic "What if Google entered your market?"), and thus something they would have had rebuttals for?
I'd argue that this isn't a retrospective in it's truest form. I would like to have a piece that's more about the metrics, like what sort of churn they got, how was their launch perceived, what sort of market research they did/ didn't do etc. These sorts of pieces would help make the lonely startup world more transparent and accessible (it's easier to do this after the fact, rather than when keeping up appearances when trying everything to keep a company alive). Perhaps Suhail will bless us with this at some point.