If I understand you right, you're saying there's a disconnect between how Jesus is suppoed to be all about "good news," when a big part of the Christian message is about sinners going to hell (which sounds like bad news).
But let me ask you this: if you had a life-threatening illness, and went to a doctor, would you want a doctor that wouldn't tell you about the disease you had? Or would you want a doctor who would tell you the truth even if it sounded like "bad news"?
Just not talking about a problem doesn't mean the problem goes away.