Why Japanese don’t have a practice to tip someone?

If you attempt to tip, there may be some confusion.

Because there is no answer that how much should be tipped.

This usually depends on his mind.

Staffs dislike these abstract things in paying because they just draw on manuals.

In Japan, they must respect customers too much.

So, they can’t be allowed to mistake.

That’s why if possible, they want a simple answer like no tipping.