Have to agree with you. Most people should use a lawyer when going to trial. Probably should consult a brain surgeon too before trying it yourself.
Neurosurgeons and lawyers are highly educated professionals. Realtors are house salesman, like any salesman. They have no unique knowledge, aptitudes, or skills, beyond salesmanship. Whereas a lawyer knows a lot about the law, and a neurosurgeon knows a fair amount about medicine and neuroanatomy, a Realtor has no more knowledge about a house than you or I could learn in a weekend (if we don't already know). They do have buddies in the appraiser's office, but we could buy that friendship, too.