The new rule is efficiency or death. Weeds lose to bushes and tree saplings that grow slower but use sunlight and nutrients more efficiently. If conditions are right, the field will become a woodlot of slow growth, long-lived trees that blot out the weeds' sunlight. Ecologists call this process succession. The successful development of one set of plants alters the conditions of success, paving the way for a succeeding set of new plants.
Weeds create the conditions for bushes, bushes create the conditions for trees.
Weedroids exploit every opportunity to gain more resources. Dendroids exploit every opportunity to get more use out of available resources. Members of a weedroid organization never worry about its mission. Mission statements are multifarious euphemisms for lack of focus. In the bounteous environment of weedroids, life is not just dog eat dog, it's hog eat everything.