JackieBlue, I don't think you can definitively translate “I couldn’t sing in the shower!” and “I’m not exaggerating. I couldn’t f*cking sing...” to Jon straight up blaming Richie for his vocal issues. It was, as the writer put it, the "long period of musical inactivity after the tour ended..." that Jon attributes to his vocal shortcomings. Jon himself has identified this "Richie scenario" as being just one factor that contributed to his somewhat depressive state - the others being the Buffalo Bills bid and the split from the record company (and probably other things too). I do agree with you that the writer appears to have some kind of prejudice against Richie as evidence by the passage: "Sambora’s departure followed a long struggle with drink and painkiller addiction, involving spells in rehab and missed shows. In this he is unlike the punctual, clean-living Bon Jovi."

I myself went through some stress recently, and it manifested itself physically - I was tired all the time, developed a rash on my neck, became very squeamish around blood, and would be constantly out of breath when I was running. Had I been any good at singing, that probably would've suffered too!! Now hopefully, similarly to how I've recovered, Jon can reach a level of performance that will sit with most fans - realistically, early BWC tour standard.

So I believe it's quite likely that the Richie situation (along with the Buffalo Bills and UMG), coupled with the steadier decline we had seen since 2010, can be attributed to Jon's inability to perform to accepted standards.