(i hope youil understand my english… isnt my native language).
If Im not wrong, there is some cases when the current scaling functionality is actually do necessary.
for example, you can see the beautiful workflow shown by Cédric Lepiller with is SpeedFlow addone. Because he use modifiers for modeling, if they wil not consider the object scale/the scaling operation will not change the bbject scale, each time that youill scale the object the mesh would ruin, and if i not wrong, this problem aplly also to the screw, solidify etc.
Maybe its would be better if each modifier will has a checkbox that change between - global value/local value.
for the tool, I agree that global value should be the defult