I have created a query here:
http://data.stackexchange.com/biology/query/328147/welcoming-index
which compares the ratio of down-votes to up-votes received by new users (joined within the past 30 days) compared to all users.
It appears that in the past month new users have receive more 2.5x the number of down-votes (evil index of 2.6) compared to other users (for the same number of up-votes).
Are we being too strict on new users potentially scaring them away with down-votes, or are such down-votes to new users necessary to maintain quality?
My personal opinion is that while quality is important, there are better ways of encouraging it than downvoting the newbies.