While I completely agree that these two tracks should have been on FRONTIERS, and that it would have been an even better album for it, I have to ask where you got the idea that they were "rejected by the record label"?

From what I read, these songs weren't rejected - they were specifically held back in a decision by the band's A&R man, and Journey, themselves. Since the songs were so strong, it was deemed it would be better to hold them back for future inclusion on soundtracks and such, rather than the two songs that ended up on the album. And to be honest, I don't think either the VISION QUEST or TWO OF A KIND soundtracks would have sold nearly as well if the songs being promoted off them were "Back Talk" and "Troubled Child". I believe in the end, The band probably made more off them this way, than had they been included on FRONTIERS. Plus, it kept their name and music out there between albums.

The question, ultimately, would be would FRONTIERS have ended up selling more (or enough more) copies with those two songs on it than it ultimately did? And even if they were on it, would they still have been released as singles, and given the same chance of recognition? While FRONTIERS could have ended up an 'all killer-no filler' album by having "Ask The Lonely" and "Only The Young" in place of "Back Talk" and "Troubled Child" - I suppose the decision was made that they could afford a bit more filler in favor of a latter day payoff.