[quote name='Conan' timestamp='1377624340' post='2189579']
Do we have any theories as to why that might be?
[/quote]
Yip.
In't old days - and the golden era specifically - they were consistently writing and jamming AS A BAND (Apologies for shouty capitals - can't get italics :-) ) in soundchecks and the studio.
They would spend time on the songs, try them out live.. refine them, tweak them, throw out the bits that don't work. And, more importantly, develop the melodies and the syncopation of the words.
These days, they have X amount of time booked in the studio. They turn up, shunt all their ideas together in ProTools, and slap a half-formed melody on top with forced, wooden phrasing that doesn't really fit.
And, on the last album, the producer conducted Neil while he played the parts. FFS.