It's pretty common to have more than one set of monitors in a control/mixing/mastering room.
The idea is to have a main set to adjust the sound just right and alternate speakers to get a "real world" idea of how it will sound.
This wouldn't be needed if everybody listened on a great pair of speakers but the majority of the music buying public listen to set ups that have little or no bass and hyped up treble (car stereos, earbuds, laptop and TV speakers).
This doesn't mean that the music is tailored to the lowest common denominator, but, you don't want the important stuff to be lost or screeching.
This process is called "translation".
Actually, those Genelecs are pretty high class for what they're being used for.