Because he looked at our hearts, our actions, and saw us as sick, needy, weak, sinful, blind and lost. This was Jesus' stated view of us, which we don't like. But you also need to see his actions about it. It's not distant judgment or condemnation. It's not uninvolved, nor unsympathetic. Whether you agree with him or not, he saw us as desperately in need. He saw our lives as not working properly. Not living in fullness or living out the goodness he created us for.
Believing that we needed to be saved, needed to be forgiven, he went to incredible lengths for us. On the cross, Jesus didn't just suffer and die as a symbol of love. It was necessary, in his view. It was either we die--eternally separated from him because of our sin--or he dies, so we wouldn't have to. So we could be forgiven. So we could know him, eternally.