Of course this proverb is not to be taken literally. It doesn't mean a speaker of truth does not even have a single friend. It's an hyperbole. That is to say it's a deliberate exaggeration to create a certain emphasis or effect. In a world where people don't like to be confronted with the truth, those who speak the truth are often orphaned. But before you use this proverb as your pretext, be sure that what you speak is really the truth and not your opinion or preference. Don’t treat an opinion as truth. And don’t treat the truth as an opinion. The truth is not an opinion and an opinion is not the truth. An opinion is what a person thinks about something. The truth is that which agrees with actuality. It is the sum of motive, deed and words. Speak the truth, but do so in love. My observation is that most people who speak the truth don't use tact. And those who use tact don't speak the truth. Tactfulness is being sensitive and sensible in dealing with people, and truthfulness is being straight and sincere with them. So speak the truth tactfully. It may not get you many friends but it will get you the right friends. Be encouraged!