i guess insofar as the rubric i use is my own, there's always going to be a layer of subjectivity, not to mention my own [classically] untrained ear is clearly flawed and probably biased towards western/northern hemisphere structures
but i would say objectively i count in equal parts technical quality of instrumentation, lyrics, song structure, and the je ne sais quoi "it factor" where you just know it's a hit or not
so the reason i count off florence and the machine is partially the platitudes of their lyrical content and the generally melodramatic atmospheres
i still like them as competent songwriters, she has a great voice, and they write catchy stuff i can listen to closely or in the background and like