As is often the case, we have to agree to disagree about Yngwie´s ability to play guitar with feeling. I think he does exactly what is right for the song (most of the time) and he touches my emotional node but not yours. To each his own.
As for his attitude - I don´t like egomaniacs and I do wish he would adopt a slightly less arrogant attitude - but believe it or not, I don´t think it´s true that he can´t get a quality vocalist to work with him anymore. Rumour has it that John West was in the frame to get the gig before Boals, but Yngwie felt West had an ego problem! If you´ve ever heard any John West vox, I don´t think you could say he wasn´t a class vocalist. Previous posts have said as much - Yngwie has been a stepping stone for many a vocalists career....