If one of you postings or comments sits at 0 points I always wonder how many voted it up and dow. Or phrased differently: Was it uninteresting or controversial.

If it sat at 1 point with 51% positive I'd know that about 100 people voted on it. For p=percentage positive and k=points the number of upvotes is $kp(2p-1)$.

So I recommend against leaving a comment or posting at zero when it is obvious that some voting was going on.

Two rules:

If you come across a controversial posting with zero points vote it (whatever the direction). If you see that you are the only voter (percent positive 100%) you can still unvote it.

If you encounter a score of -1 or 1 and want to vote it to 0 then use any random process at your disposal and vote only with 50%.

These two rules should have the effect of avoiding permanent 0 while still not hindering crossing 0.