^The music had a lot to do with that. By the fourth season, most of the musical scores had lost their bite. Melodies were gone, and much of it felt like filler. It made a lot of episodes feel plain.
Actually, the opposite is true. Season 4 features some of TNG's best scores. Ron Jones composed some of his most memorable music for episodes like BOBW2, Final Mission, Devil's Due, Night Terrors and of course The Nth Degree. Guest composer and future replacement for Jones, Jay Chattaway scored Remember Me, probably his best score ever. And even though Dennis McCarthy's scores began to sound familiar, they were still exciting in season 4. As soon as Jones was fired near the end of season 4, the music changes dramatically. But by that point, there were only 4 or 5 episodes left in the season. The sonic wallpaper sound became part of the show during season 5, not 4.