Trees sound good on paper, but when in the game:

1) Some people will ask for the best way to do the tree
2) Some people will demand that you be a certain spec or else you won't get invited
3) Some people will look online for the best spec you can do for a specific job.


4) Very few people do the opposite of what the "norm" says and they do what they want regardless

In the end Spec trees are no different then a predetermined setup.