Mozart is just an example, there are many famous people with similar or even more tragic stories - Tesla, Oscar Wilde, Van Gogh, Kafka, etc - just to name a few everyone knows.
What am I talking about? What is my point? Not just about God as depicted on someone's avatar, painting or whatever. If life is just a random event, with no "bigger picture" involved, then we really are not too different than the mentioned worms or roaches - we run around this planet without much sense or purpose. In 50 to 60 years, >90% of MTF users (for example) will be dead anyway; what kind of life they had, whether it was "improved" or not matters little. Do you know what kind of life your ancestor from XII century had? Or your ancestor from VIII century b.c.? Do you care? 5000 years later, is anyone going to care what life we had today, did we do our duty or whatnot? Doesn't really seem so in case of random life.
To start with, it makes a difference for you
Yes, we are animals. Yes, most of us will probably be forgotten eventually. While we're here, however, we have the chance to give our life a sense and a purpose.
You seem to be saying humans are unable to find a sense or a purpose for their own lives in a scenario without a deity. That anybody could think that I find extremely sad.