They certainly had the best marketing, though.
While Gene Simmons hasn’t explicitly called KISS a “bad band,” he has been very open about the fact that the band’s focus was more on the live experience and entertainment than on creating consistently great albums. He’s acknowledged that Kiss never spent enough time in the studio and has even called one album “dishonest”. He also mentioned that the band, in his view, was meant to be a spectacle and not necessarily high art.