We all screen/filter our purchases, be it by cost, class, power, etc. because we can’t listen to every product on the market. Objective performance is just one possible filter, though it also is a logical choice because measurements say a lot about how an amp will perform with one’s speakers, to some extent how it might sound based on its distortion spectra and distortion behavior.
Screening products on such a basis is rational, efficient, and in my experience, a meaningful and useful exercise. I want an amp that has enough power, adds as little as technically possible to the input signal, doesn’t change character with load, and will function without issue with my speaker’s impedence. Of course, once I am comfortable that it meets my objective needs, I listen and base my decision on that. So, yes, my ears are exactly the final arbiter...Sure, I could take your advice and ignore the specs, just audition willy nilly, find out the hard way that the amp won’t meet my objective needs, and waste a lot of time and money. Now that would surely be sad. No thanks.