If your bike is fitted with an alarm, even one with a battery 'safe' mode, your bike will last 3, maybe 4 days before the battery will be dead.
It is not good for a battery's life to be constantly run down then recharged again.
For anyone that cannot ride every single day, a device such as Optimate would be a good investment and would prolong the life of a battery, not to mention that your bike will not have a flat battery the day you want to ride it.
Jump start a Rocket, anyone?