Very much a subjective thing. One man's meat is another man's two-veg, and all that. And there's a world of difference between bad songs and songs I don't like - there are songs I can recognise as good even though I can't stand them, and songs I really quite like even though I accept they're not very good as songs.
And I'm sure there are people out there who love all the songs put forward here as examples of the worst. People differ. Learn to live with it.