It is clear that some people like it and some people find it annoying. Sounds to me like this would be a perfect candidate for another option. All kinds of features can be enabled or disabled, so why not this one? So everyone can play the way they prefer.
I myself would love to opt out. Knapping a tool is fine. Knapping arrowheads is quite something. And i bet there are even more time-consuming things. Not everyone has couple hours for clicking on cubes.
An alternative (configurable) modification to the system could be introducing a "brush" kind of thing, that knaps multiple cubes. In clay forming this could also avoid forming wrong forms. So we still do the activity, but it is much faster and easier.
