I have to discuss this issue with my team, but the problem with free hand tools is that you lost the benefits of the parametric distributions.
I mean: you can scale or modify easily the items, but what if you want later to make grass more dense, replace models, adjust a cluster, etc ? That's not posible, because items as defined as independent elements (with their position, scale, etc). Your suggestion would fit more as an improvement of Custom Edit mode (what it's other possibility).
Instead, using Forest Areas you have a Paint tool to your disposal, but internally it works "painting" a spline. In fact, there are options to convert a Paint area to a Spline and back.
For example, in the previous scene you can convert the spline area of Forest002 (inner object) to a Paint area, make you changes and everything is updated automaticaly.
I know that both methods are very different. I just want to show you how the parametric approach can be much more versatile, specially if you need to make changes later.
Of course we appreciate your comments and feedback, specially if the proposed workflow doesn't suit well with your needs.