A catchy tune doesn't mean it's quality music. As a general rule, mainstream is always shit. Always has been, always will be.
i disagree. there seems to be a lot of close-mindedness towards pop music. it's almost like it's become this abstract monolith that people just hate without even knowing why besides that it's "commercial". there are a few mainstream pop artists who do make good complex quality music that shows a lot of talent. case in point is usher, whose productions i think rival those of producers in the edm world.
of course there's also the really shit music, and on the other end of the spectrum is david guetta, who came out of the edm scene, turned pop and now thinks making a 2-bar melody makes a good song. not that a simple song can't be good, it just needs to be done properly. there are a lot of simple pop songs that are both catchy and pretty good.