So, I often vote on posts when I come back to the frontpage a few hours after I've read a post, they also serve as a valuable function to new users by indicating that you can vote on posts, and they also help you keep track of what you've upvoted and downvoted.
None of these are essential features, but they are things that make me hesitant to just remove the functionality. I think something in the range of only showing them when you've visited a post seems better to me, and something that is easy to activate as soon as I've fixed our view-tracking system (which will happen in the next two weeks).
Enabling voting on the main page encourages people to vote before they've read an article based on things such as the title. This is bad for a community that aims for substance. It would not require very much effort to hide these buttons on the main page.
As an alternative, we could choose to leave these buttons up if you have actually clicked into the page and just come back, but this is much more complex and probably not worth the effort.