Here's a list of similar / duplicate requests on the main Meta.StackOverflow site:
- Shouldn't a rep-less newbie at least be able to upvote a good answer to his/her own questions?
- Allow upvote for <15 rep users on own questions [closed]
- Allow new users to vote on answers they've received [closed]
- Why is 15 reputation required to upvote?
I guess you can read through them to get the idea why users want the ability, and why it is declined.
The main idea is: With 1 rep, you haven't gained any trust yet. The site only trusts you voting until you've proven that you've understood the system (i.e. by asking a good question or posting a good answer).
