Samsung was not increasing any performance of the processor for any tasks. Samsung is allowing the processor to run at its maximum potential, which is a natural and reasonable way to provide a benchmark.
It is very different from your examples. Samsung is not artifically using different hardware than what customers get. Samsung is, instead, using a benchmark as a means to measure the maximum performance of its hardware, the same hardware customers buy.
Nowhere is written that the system should allow a benchmarking application to measure the performance as if it were a normal application. As I stated multiple times, anyone is free to consider benchmarks with their own perspective, and the maximum performance is as valuable as any other one.
You mention that "Customers will never see that extra performance", but you are missing that the result of a benchmark does not provide any clue to the customers about the absolute performance of a system. Benchmarks do not provide day to day usage information, they are used to compare different systems under a certain criteria, and Samsung has chosen to provide maximum system performance.
You seem to be avoiding to answer what I wrote two times now.
I just did.
Samsung chooses to use all the processing power available to run when benchmarks are running. Also, care to show a source detailing how the process for which "smartphone processors are limited from their max performance in order to conserve power" work?
As for the reason, you may as well ask Samsung. Probably it's for marketing, and they have the right to do it, since no standard of norms exist to support one way against another one for benchmarks.