It isn't good to be alone, but sometimes circumstances require it. Faith in oneself and one's mission in life helps dispel the agony of loneliness. The Torah cautioned human beings against attempting to be successful in life by going it alone.
Loneliness leads to poor judgment, bad decisions and a depressed state of mind.
It also breeds a contempt for others and a cynical view of life. It is not a good thing. For most of our history, the Jewish people have been forced to go it alone. Bilaam's prophecy certainly came true. There are some positive aspects to going it alone.