If there was one element about The Beatles that I admired more than anything else it is that they are the most efficient songwriters I have heard. With the exception of Hey Jude (where their lapse of repetition is understandable although not forgivable considering how transcendental that melody is) every song by The Beatles is as long as it needed to be. Even lengthy songs like I Want You (She's So Heavy) that some people may argue to be repetitive have lengths justified by their variation of theme in the first half of the song (despite repeating lyrics) and by Paul McCartney varied increasing intensity of bass playing over the repeating guitar riff in the second half.
One of my favourite music quotes of all time was by Johannes Brahms with "It is not hard to compose, but what is fabulously hard is to leave the superfluous notes under the table'
I don't think there's any pop writers that emphasise it more than The Beatles.
You think that with Beatles as the blueprint of pop music and their supposedly "influential" status (if anything Beatles aren't influential enough) that subsequent pop writers would used them as the model to write tightly pack, efficient compact songs. The axiom of keep the song short and sweet or keep it varied should be the basic principle of all songwriting/composing.
What we actually see is that the length of a standard pop song has increased to the 3-5 minute mark to the extent that when the Pixies decided to write 1-3 minute songs it was considered bizarre as seen by this quote from wikipedia
"Norton's suggestions were not always welcome, and several instances of advice to add verses and increase track length contributed to the front man's building frustration. Eventually, Francis took Norton to a record store, where he handed him a copy of Buddy Holly's Greatest Hits, in which most of the songs are about two minutes long. He told Norton, "If it's good enough for Buddy Holly ..."
Now this expansion in song length would be perfectly fine if this resulted in more ideas being packed in the song. However a pop song still follows the same format today as it did back in the 50's and 60's. There's the verse/chorus +/- bridge, instrumental break, intro, outro. The form hasn't changed, just the length. Normally the extra length is filled up either with a) Extending the verse - Instead of having the verse consisting of 2-3 vocal lines/phrase (when Beatles write often each phrases have their own distinctive melodies), the phrase/line goes even longer, usually consisting of one melodic line and then repeating it with every phrase. b) having multiple verse with no instrumental break or bridge or variation in the verses (aka Fake plastic trees by Radiohead, each verse is a gradual increase in intensity) to break up the monotony
The reason why this frustrate me is that there is no such thing as "free" music even in this downloadable/youtube era. All music cost time and time is precious. Therefore good music should not waste my time and padding out songs with superfluous material is wasting my time.
So when I'm thinking about how on earth did this trend of expansion of song length with fluff and who was responsible of starting this trend. The earliest example of songwriting padding in mainstream rock music I can think of is Bob Dylan's highly influential (and admittingly great) Highway 61 Revisited. All you have to is look at the song length of that album and you see 4-11 minutes songs scattered in the tracklist and often the songs are just verse/chorus (normally with no bridge at all) with each verse and chorus musically identical to each other
I guess what Bob Dylan innovated and inspired subsequent songwriters is to create the idea that lyrics is important in music. Therefore if songwriters created lots of lyrics and they should expressed all of it in their songs irrespective if they have enough music ideas to sustain the song length or not. Due to this innovation, 2-3 minute pop songs became the 3-5 minute pop songs.
It's part of the reason why I have a love/hate relationship with Dylan. For one thing I love his voice and I love the atmosphere/mood his music creates, his normally tuneful and occasionally sometimes I'm even impressed by his lyrics when I'm paying any sort of attention to it. However he was one of the worst influence in pop music due to complete lack of pacing and efficiency in songwriting. I listen to his music in a way other people listen to ambient music that I sort of just close my eyes and let the atmosphere of the song carry me away and the fact that is actually a good vocalist and vocal melodies makes it more tolerable compared to actual ambient artist (by the way this is why I believe Bob Dylan writing a mostly instrumental soundtrack album to be highly logical instead of a bizarre diversion that most people seem to think it is).
Gah - I have to admit that the negative influence of Dylan has even indirectly negatively influence me where a lot of my songs I've written 5-10 years ago go for 3-5 minutes with not enough material to justify song length apart from narrative/lyrical coherence. Where I personally sacrifice music pacing for lyrical reasons and this was before I ever listen to any Dylan songs. Damn you Bob Dylan you made me hate my own songs!!!