There are many different styles of preaching ranging from "way too boring to ever be effective" to "way too loose to convict". One of the most common styles of preaching today are the "feel good" sermons. This is where the sermon is directly aiming for each listener to walk away feeling good about themselves. On the other hand no one one wants to hear a preacher yell at them every week and walk away feeling depressed.
There needs to be a balance in conviction and encouragement. The word of God should never be softened or hardened. The word should always be presented as what it is. Preachers have the opportunity to change the way people's hearts... but they should always remember it's God's word and power that changes hearts.... not the preacher!