Although I think more voting (up and *down*) would be a good thing, I don't think it should be done to make SF "warmer" and more welcoming.

I think one reason for low voting is that professional sysadmins usually don't have time and money to do everything, so we prioritize quickly and harshly.  When people see a question that's not bad enough to downvote, but not clear or complete enough to answer, they probably move on or maybe leave a comment asking for more information.  

This makes the bar for "good" questions quite high: questions have to be on-topic, *and* they have to be clearly expressed and have something interesting about them to get someone to upvote.  More obscure topics (like Notes, also HP-UX or VMS) are going to get less interest.