Why the coins name was changed? Devs wanted to clean the reputation? Was there an objective reason?
Several of the stakeholders felt the new name was a better marketing vehicle and in addition the old name had been heavily cyber squatted. Two votes were held first on IRC and second on this forum. Both votes were in favor of the change.
When did the coin name change?
It was launched on April 18, 2014. IMO we can call this currency a youngster in comparison with Bitcoin.
Changing the coins name was an attempt to clean its reputation a bit, don't be so naive. Monero devs are very cunning.