On the subject of Ralph T... timing is everything.
That article pretty much hits every point. It's also why everybody's follow-up didn't pop. Because it was time for the NE reunion but they decided to give it another go. Meanwhile, other things were happening in R&B: Jodeci, TLC, Mary J. Blige, R. Kelly, BoyzIIMen, increased sexual content, increased hip-hop influence, new jack swing is declining... all of this happened between that 1990 wave and 1993. They were kinda still in their 1990 mode while everybody was moving on.
So as it relates to Ralph... a 1987/88 Ralph album would have done much better than a 1990 Ralph album after Bobby, BBD, and Johnny. And some people think Ralph's album bricked, which isn't true. It just didn't do Bobby/BBD numbers. And around that time, hardly anybody was doing Bobby/BBD numbers, and Bobby/BBD never did those numbers again either. Every NE side project spawned hits, including Ralph's... anybody that says they didn't weren't there. But his style was fading at that time- it was the last time Freddie Jackson made hits, last time Anita Baker was big, last time for Jeffrey Osborne, R&B was 'let me lick you up and down til you say stop' within 2/3 years.