Weak Bosses

People who are unsure about themselves or want to suck up to his or her bosses are the worst bosses themselves. I find many around our work places who use loud voices to put their point through as if loud voices lend more weightage to their logic (actually it is not so, but because logic is missing they will use loud voices to subdue the weaker voice of the junior). Then I find themselves being careless in their own work and landing into problems but when it comes to handling their own juniors, these chaps will act as if he never makes mistakes!! Then I have also seen another category of people (not necessary that all these characteristics cannot be in the same person- and more often it is so) that they will discuss many issues - again in aloud voice-- pretending they know everything when they do not even have the inclination or time to make their own research to see what is what. It is very easy for them to pass judgement on everything that comes to their notice sply during tea time and act as if he or she was the last word in the matter. What stops us to do our own research and then make comments? What is the need to make comments on matters which we do not know? Is it absolutely necessary to prove that we know everything since we are bosses?