I just can't reconcile this in my head

Yeah, I suppose those songs are honest at least. Still though, that doesn't make it ok. There's a lot of bad thoughts people have (like racist or homophobic thoughts) that they don't openly admit to, let alone release as a global hit song. I wouldn't be so hard on yourself, it's extremely rare that someone would even realise they value people based heavily on how they look, let alone realise how bad that is. Plus it is an inherent human quality to do this, it's genetically built into us to seek out the most desirable mate. It's in our nature, and nature is often cruel. Plus we've been pummelled by this message that looks are important by the media since we were very young children, it's near impossible to overcome that completely. All we can do is to try to be more aware of it in our everyday lives, and try to realise when we judge someone based on their looks, and then to stop doing it.