I think Journey was a much, much, much more interesting musical outfit prior to Cain joining. They were more adventurous, and willing to explore.

Once Cain joined, they really turned into (often but not alwyas quality) bubblegum rock. I cannot think of a better example of a band that had such a high amount of unused high musicianship than Journey. They had a wonderful singer (listen to his line of "We Are The World" to hear how brilliant he could be. Not always served by the best or right material though), a superb guitar player and amazing drummer... and they ended up known for syrupy stuff like "Faithfully" or "Open Arms"....

I am not a die-hard fan. I believe that there are a lot of fillers in their catalogue, and that the really brilliant songs are few and far between. What actually saved a lot of the songs was the brilliance of Perry, Schon and Smith. They managed to bring some soul into often very bland pieces of music.

I am fully aware that Cain was the one who actually brought the commercial success to the band. However, to me, he actually sucked the soul of the band dry.

Why didn't they have hits after Perry left? Because they did not manage to find a singer who could bring soul to their music, and also a drummer who "jazzified" their sound. Once Perry left, they became more of "AOR by numbers" band. Still good songs, still very good musicianship, possibly a rockier edge, but much less soul. And I think the masses in the 70's responded to the "blackness" Perry, Schon and Smith were giving the music.