I think their point is that you are not actually doing more work. You are seeing higher credit due to an inflated benchmark, not due to extra work processed.
At least that was how I understood it.

I'm not judging you or any others, I'm just trying to explain what was told to me, and why others perceive running optimized windows boinc as "cheating".

Oh, I agree with you about slow pc's getting big points because of the time it takes them to run a wu. It doesn't seem right to me either.
Like I said, they just need to give wu's a certain point structure and award points by "finished" work.