Balancing Dissonance With Consonance

Just read a book on the healing abilities of music and it evokes some thoughts in my mind. Over the years, dissonances have been used in music, to evoke tension and despair. Just by changing one note in a major chord, we get a sound which would break our hearts. In most traditional music, dissonances will be resolved somewhere in the piece, by returning to normality. Composers are probably holding the mentality that life is too short to be continue lamenting with pessimism. Such music infuses hope and faith in the listeners, are uplifting and regenerative. Now, for the other side of the picture...

Recently, atonalism came into the scene. What is going on in the modern composers' minds? It seems that music full of dissonances sprang up in the period between the world wars. For most people, atonal music causes them to cringe in disgust instead of feeling anything which you would call emotion and leaving them cold. Why such a reaction from the people? What exactly is in that sort of music? Maybe what the composers are trying to do in their music is to put in as many emotions as possible into one chord. With so many emotions in one chord and the natural human inertia to overwhelming changes, it's probably why listeners will just form this emotional barrier to such music and block out all the overpowering emotions. Are the composers being disillusioned by the problems they see present in the world, that they just decide not to have a key signature to return to after the rollercoaster rides for they see no chance of the problems in the world being resolved, or are they just sick of the peaceful music that they just decide to pull out of tonality and venture into the unknown? Maybe to appreciate such new music, one needs to have a very open mindset and accept all the emotions that's being directed at them by the musician. But I certainly hope that such music can be kept to a minimum in the concert hall, but not eradicate them completely, for I have no wish to see that the concert hall become a place of terror and dread for the arts lovers.