...once you touch that first treetop you are no longer in control of where or how fast you stop... You have no control of branches coming through the front windshield before you get close to the ground. There are far too many unknowns.
...
Landing on a lake the number of unknowns are limited. You know you'll get wet and cold, things you can plan to deal with. If you have the skill to dodge a tree, you should be able to put the aircraft close enough to the beach that it will be a resource after you escape wet but intact. Being intact is a very good start to being rescued.