Harman research has shown that most people prefer neutral sound, but that a neutral sound has a slightly downward tilt in the in-room frequency response. Additionally wide directivity and a smooth power response have also been correlated with favorable performance.
The Klipsch RP-600M fails according to this "most people" standard.
Scientifically,
the most popular car in California and Washington State is the Honda Civic.
the most popular car in Arkansas is the Nissan Altima.
the most popular car in New York is the Honda Accord.
https://insurify.com/insights/most-popular-cars-by-state-2020/
What is important isn't that mass market doesn't translate into sports cars/SUVs/trucks, but that even the mass market can come to different conclusions.
The hype isn't coming from reviewers who are being paid to promote products. The hype is coming from
- sighted bias. US reviewers will always try to like US-branded speakers.
- reviewer subjectivity (i.e. some people like the distortion of tubes)
- poor level matching. The sensitivity is lot higher for the higher frequencies, so if something in the 250-500 Hz range seems like it's level matched, the Klipsch will play louder in the higher frequencies.
Amir noted "Dial in some simple EQ though and the speaker transforms into a beauty" which may help for reviewers who were testing in a home theater environment with EQ.
The advantage of the measurements at AudioScienceReview is that you can see the strengths/weaknesses of each speaker design. You may prefer coloration and that is OK.
The BBC dip is another good example. Some people think speakers sound better with a BBC dip. Others do not.