Tiger has more talent and knowledge and experience of golf at the very highest levels of play than anyone except a Nicklaus or Hogan. The reason Tiger has such suspect instructors is a little complicated:
1) the instructor has to be connected with whatever Instruction magazine Tiger is connected to.
2) the instructor serves the same purpose as a pony or mule in the same stall with a great race horse; to calm him down.
3) Tiger, though highly intelligent, is not totally aware of what are the illusions and what are the facts/laws, etc. of golf. He uses the illusions better than anyone except maybe Johnny Miller
4)Whereas a Sandy Lyle or a Ralph Guldhal might be totally overwhelmed by the prattling half truths and shallow mendacities of a "famous" instructor-- Tiger is virtually immune to that poison.
5) Tiger is wired in such a way that the cliches and banalities of golfspeak don't have a bad effect.