“correct me if I’m wrong, I think it’s called bitul Torah to involve oneself with Neviim and Kesuvim instead of Gemarah”
Learning NaCh is Talmud Torah assuming you learn it according to the understanding of our sages rather than the heretics.
” many of us don’t devote much time to NaCh”
The OU’s Nach Yomi program is actually finishing Navi today. I am a day behind and will finish on Shabat.