Leaving neutral tag on shit posters as early warning for them is good. Shit posters sooner or later will fall into burst posting or plagiarising, so if DT members tag them with neutral trust, and leave a warning mesage for them; they will keep their shit works. Eventually, someday, if they get punishments by plagiarism or something stupid, they won't have chance to blame on anyone else. Maybe, it is one of the way old users help newbies in the forum.
I used to tag spammers. Back in January of last year. That took a horrendous amount of time and I didn't even crack 1% of the total spammers on-forum.
The neutral tag will be even less impactful and still take an equal amount of time that could be used to (instead) report posts.