I'm sure I know what finishing is for.
Finishing a project refers to the final steps to beautify and preserve it, such as staining, shellacking, painting, oiling, glazing, varnish etc.
That is a paraphrased version of the tag on Woodworking.SE. People are going to use tags incorrectly from time to time and we can't stop that with all the tag wiki edits in the world.
However here given the sheer number of crafts do we need to do anything with this tag. Note that it has not been misused as of yet. Lots of projects need to be finished but only certain ones need finishing.
As I type and think more on this it might be better just to see what happens.