I am not going to suggest that Gorecki is one of my favorite composers. But I do not agree that the 3rd is vapid, empty or naive. It fits quite comfortably into the minimalist school that includes Arvo Pärt, Tavener, Glass, Reich, Riley, Young, Andriessen, Nyman, et al. Maybe Hovhaness fits in there too.
Repetitivism has been used quite a lot in modernist music, from Stravinsky to Prokofiev and others. There are those, of course, who would dismiss the entire minimalist approach as trivial schlock, just as a lot of people dismiss serialism and modernism. But minimalism has developed pretty deep roots in the world of music at large, from smooth jazz to drone, disco to techno, etc. And works like Ravel's Bolero, widely detested by the critics but loved by the populace, suggest that there are aspects of minimalism that resonate with listeners.
Other minimalist compositions that achieved something of a hit status were Preisner's "Requiem for a Friend" and Nyman's Piano Concerto derived from music composed for the movie "The Piano." Rather than condemn minimalist music as trivial or vapid, I prefer to accept the compositions as representative of a particular style or school.
Whether it is music that I want to listen to a lot is another matter.