“It's better to be alone than to be in bad company.”

I think this means that it's better to be by yourself than to be with bad people who behave bad. This is saying that when you are alone than you will do good things but when you are with a group of bad friends than you will do bad things. The bad company are usually friends who smoke or drink alcohol and then they like force you to the same as them. Being alone you are more productive and you will not choose the wrong that way.