You may be right (although I would change "some" to "most," even so), but during the 20+ years I spent in, shall we say, a related field, I never met a single one who was able to back up his/her claims. It's telling, I think, that certified handwriting analysts (those who only try to connect specific writers with particular writings) are accepted in every court in the land as "expert witnesses," while so far as I know, such status has never been extended to even one graphologist.
I suppose it's possible I just met all the wrong graphologists...
Those who claim to divine the exact meaning of every little squiggle (e.g., that a certain shape of certain tail on a certain letter shows the writer to be jealous and acquisitive) are hoaxsters and nothing better than astrologers.