I agree with the second part of what you wrote, but I can't bring myself to lower my standards that much when it comes to low-ranked members. While not all of them are spammers, I do think that the vast majority of their posts are of very low quality and are made primarily for bounties or signature campaigns, which has been the case for years now.
Only a handful of bounties accept newbies for signature campaigns and a much lesser number than that are worthwhile.
Imo, a user should at least get to member rank before engaging in signature campaigns. It should not take a committed poster too long to get the requirements.
I also generally lower my meriting standards when considering posts made by newbies.
Could I suggest that in addition to the list of member sho most support newbies, we could make a list of newbies who received the most merits in a month, or just the top receiver. This would help users looking for newbies to merits and would hasten the ranking up of deserving users.