While agreeing entirely with the premise that "there is then no test of these hypotheses on Mars" and it seems also that any hypothesis can freely ignore any previous work, IMHO no abiological (read inorganic) hypothesis can be as complex as that requiring life. While I am one of those who "would much rather erect incredibly complicated abiological hypotheses", I think life requires an incredibly to the power of incredibly complicated for life to exist on Mars. In no way is life a "simple explanantion". Is not the DNA molecule one of the most complex on earth? Us inorganics are offering instead "basalt + sulfuric acid". The how, when and why are still to be answered - e.g I doubt the claim by the Athena team that this process took place in the Noachian and Meridiani Planum stayed pristine for 3.5Gy but that's one of those (currently) untestable hypotheses. But all far less complex than life. IMHO we must all adhere to Carl Sagan's staement that "Extraordinary claims require extraordinary evidence".