My requirements for Newbies are really low: if I think it's a real user and not a spammer, I'll Merit him/her. I strongly believe that's what Bitcointalk (and Bitcoin) needs to grow long-term.
I agree with you. Months ago, in 2018, my very first merits came from @actmyname when I joined his contest and won. 14 merits won in that contest motivated to me and I have never stopped improving myself, and slowly crawled to the top (Hero member now, and soon will be a Legendary, next few months).
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.
Yeah, it is very rarely to see good posts from newbies. I saw some users sent merits to Newbies who opened threads to ask for help, with serious questions, not to get posts. It is hard to say it is right or wrong way to use merits, but I think that approach is flexible and not too bad. Posts are acceptable quality (just for newbies) even they are questions.