The Oxford online dictionary defines 'overrated' as: an adjective meaning, 'have a higher opinion of (someone or something) than is deserved: an overrated player'. Most dictionaries, inc. OED, will define over-play as the verb, overplay, which is not helpful.
To measure the extent to which a rock song is held in a higher opinion than is deserved is difficult to the point of impossibility and therefore, as has already been mentioned, is highly subjective. For example on what basis is the opinion measured? Is it musical dexterity, artistic feel, style, popularity, radio airplay, sales, marketing, ubiquity, live performances, the judgements of journalists, the opinions of rock stars, or a combination of these? Added to this, is how do we collect the data? Which brings to mind who, why and where?
The disproportionate extent of radio airplay could be relatively easy to survey, but on what grounds should it be measured, by sales, popularity, media hype, media promotion and the like? There are rock songs which gain cult popularity despite sales. There others which gain popularity over an extended period of time.
Don't forget FM radio in the US is a different set-up to radio broadcast in the UK and continental Europe. Sweet Home Alabama and Freebird may have had frequent airplay in the US, but they were hardly played here in the UK. Their popularity grew by word of mouth and an underground following. They also had very tentative press coverage, if any. Indeed, they are still neglected here; I remember Street Survivors being in the sales bins at the time the key musicians were killed in an air crash.
In the UK a combination of press opinion and record sales are often taken as arbiters of good taste, which seems highly unreliable. However, if a song is widely held in high esteem, such as Black Dog or Stairway to Heaven, (in a way which has a ring of truth) why shouldn't it be highly rated? They are not my cups of tea, but that is not the point. The same could be said for enormously popular and big selling records like Born in the USA, Frampton Comes Alive and The Wall. The only proviso I would add here is when a song from a particular genre is rated at the expense of others, ie punk rock over progressive rock, or when the song just advocates killing cops, beating women and whatever else.
One of my favourite quotes is from Robert Graves who said Shakespeare is a very good poet despite everyone saying he is. This (as very good songs) applies to The Beatles, Bob Dylan, Bruce Springsteen, Led Zeppelin, The Rolling Stones and others. I love some of them, but not necessarily all. That doesn't make their songs overrated in my opinion.
Apologies for making this verbose, but, finally, isn't this a negative thread which invites negative comments? Sorry Bruce, but couldn't one person's fun be another's inflammatory remark, especially as what constitutes 'overrated' rock songs is difficult to define?