The concept of your stack size related to the cost of an orbit will never be obsolete. That's nonsense.
However, it may be pointed out that deciding just how desparate you are can vary from situation to situation. Here, Arnold Snyder explains about his view of M:
http://www.blackjackforumonline.com/...egy_True_M.htm
I find Snyder to be a slightly too desparate too early for my taste and a tad too aggressive (just read his book). My play falls somewhere between Harrington and Snyder and does depend quite a bit on the tourney structure but also how the others are playing.
I also believe Harrington is criticized more by the younger players of today who feel that loose/super aggressive is the best way to play in today's game (perhaps a macho/ego sort of thing?). In other words, I find a lot of it to be the younger set giving jabs at the tight old fogies who seem to never be in a pot.