Why is philosophy so scary?

It never ceases to amaze me the stigma that people have when it comes to the field of philosophy.  I teach a 10th grade philosophy class, and every year at parent orientation when the parents come to talk to the teachers of their students that year, my section of philosophy is full of parents that all have the same look on their face.  That look that says, "What on earth are you teaching my child?"  The concern is real, as well as the stigma.  What is philosophy? 
http://dictionary.reference.com/browse/philosophy

1.  The academic discipline concerned with making explicit the nature and significance of ordinary and scientific beliefs and investigating the intelligibility of concepts by means of rational argument concerning their presuppositions, implications, and interrelationships; in particular, the rational investigation of the nature and structure of reality (metaphysics), the resources and limits of knowledge (epistemology), the principles and import of moral judgment (ethics), and the relationship between language and reality (semantics)
2.  The particular doctrines relating to these issues of some specific individual or school: the philosophy of Descartes
3.  The critical study of the basic principles and concepts of a discipline: the philosophy of law
4.  Archaic , literary or  the investigation of natural phenomena, esp alchemy, astrology, and astronomy
5.  Any system of belief, values, or tenets 
6.  A personal outlook or viewpoint    
7.  Any of the three branches, namely natural philosophy, moral philosophy,  and metaphysical philosophy, that are accepted as composing this study.
8.  A system of philosophical  doctrine: the philosophy of Spinoza.
9.  The rational investigation of the truths and principles of being, knowledge, or conduct. 

The last definition seems to be the easiest explanation that I can give to parents that seems to ease the fear.  Of course I have some problems with any definition of philosophy, including this one.  First the second word, "rational" seems to be a very subjective word.  What seems rational to me, may not seem rational to you and vice versa.  There must be more work done to ensure a complete understanding of what is rational which I will discuss in another post.  I think that we all agree, by this definition, that philosophy is something we do every day.  We are constantly trying to investigate the truth of ideas and reality.  We all want to know the truth, and whether we agree or not on what is truth, we all agree that truth is important and worth knowing.  So the idea of philosophy should not be scary.  Now the implications of those who partake in philosophy may be scary depending on the process of "rational investigation", especially when we start talking about how we exist, what we can know and how we can know it (epistemology) and how we should act.  Everyone has a different opinion.  But this could be what makes philosophy interesting and fun!  Do not fear the search for truth!