I don't think it's even possible to generalize this to a nation. You could theoretically determine it as an average by the nation, but getting this information is borderline impossible, as its entirely the perspective of the applicant.
And without this kind of data you're basically left with a few anecdotes, which entirely depended on the mood of the worker that handled the case of the person providing the anecdote...
When I go through border security at an international airport, I usually can see what is happening at almost all the control gates... So even as a white man I have ample time to see the behavior of border security guards with others.
And yeah, the cliche of AMericans being haughty gung-ho cowboys is true. They bark at people and clearly play the bully.
None of my Indian friends who have applied for and received Japanese visas had anything negative to say about the process, so I don't know what you're alluding to.