I've considered it. May do it yet.
As to securing it when you are away from it, there are locks, etc., just for that purpose. People ride scooters and bikes all the time for work, etc., without problems.
Rain may be an issue, but it is more a personal convenience thing - some folks ride in the rain all the time, others don't.
The one thing about scooters is the size. There are some that can only go up to 35-40mph. That could be a problem in an area with lots of 45-50mph speed limits. The ones that go 55+mph may require a motorcycle driver license (if California, the slower ones don't require the motorcyle license).
You might see about renting one for a weekend and see how you like it.