You should shut up and see what some people are getting done.(Farming 101)
With that statement you just became a member of the group you seem to dislike.
It is but unfortunately much of what is taught and learned are bad habits and bad techniques backed up by nothing more than belief and opinion and they are passed on to others who then learn bad habits and bad techniques. So this site is like you thought it was but unfortunately thanks to many it is largely a university of growing ignorance.
You are the thread starter, not the thread owner, operator and moderator. Every thread here is open to every single member and each has an equal right to express themselves as do you regardless of if you like that fact or not.
That percentage will vary from person to person depending on how they want to use their plants and or to what degree they are capable of using their plants and to some totally dependent on their chosen/preferred growing technique. To someone who makes hash lots of leaves with trichomes on part of them to all of them is pure gold and to someone else the leaves are pure waste and to others they are seen as an unwanted waste long before harvesting. ("Waist" as you put it is the narrow area between the hips and chest, what someone's belt size or pants waist size would be and not a waste product, something lacking worth or value or something usable, of value, worthwhile that goes unused.)
As odd as it might seem, some people have known what you call; "farming 101" for decades. But it is always nice to see something very old brought up again now and then.
Too late ... they have been here from the very beginning. If you want none too be here, for that to happen you would need to exit your own thread.
If you are familiar with your old saying; "you catch more flies with honey than vinegar" you may care to pause a moment and consider it and then you might care to soften your phraseology a bit and drop the abuse or else with this crowd it is likely to come back at you tenfold.