The faster blocks make sense though if you want to protect yourself from Earth miners (see discussion in their forum under "Evil Earth Miner Scenario".
Except it does nothing to protect you...Earth just needs more hashrate, and their blockchain trumps Mars', no matter how delayed.
The retargeting is similar to 540 block coins, like Terracoin.
Imitating a scamcoin which has had problems as a direct result of the change, is not the best idea 
Regarding the coin supply: it aligns with the departure of the Marscoin blockchain to Mars:
Why is this a good thing? I'd think it make more sense to have most of the coins mined on Mars itself, not most on Earth...