It makes sense for them to use speakers they are familiar with (esoteric or not), that way they can compare the sound of different amps, it works the other way also, they would use a setup they know the sound of, to compare to other amps/DACs etc.
The good news for you is, there are plenty of folks on this and other sites that can tell you their real-world experience with setups that might match what you are looking for. It helped me to match a new amp to my speakers.