Jeri, I feel the same way you do about 20 somethings but it humbles me to realize that Joni Mitchell wrote "Clouds" before or during her 20's. Maybe not everyone will agree with me that this is a wonderful song. Can't say I like her todays stuff, though. When Janis Ian wrote "Society's Child" as a teen-ager, I was rather moved by that song. Once in a while seemingly age-less songwriters come along.
I think the problem is that the Singer/Songwriter has been boxed into certain kinds of tunes with reflective lyrics and an antidote for this would be if the S/S would take up another instrument such as jazz piano or accordian. The Berrymans impress me as interesting S/S because they are witty and not given to the usual S/S sound. Maybe an S/S might try accompanying themselves on just an accoustic bass. This is one way to find out if the song holds up. Even an acapella S/S might find a niche. It worked for traditional folk singers.
I think one of the problems with the S/S's today is that the melodies tend to become similar to one another. I would like to hear some songs in different time signatures such as 9/8 or even 12/8. The melodies of today's singersongwriters are up for comparison with the likes of George Gershwin, Richard Rodgers, Cole Porter, Hoagy Carmicheal and Berlin. The S/S lyricists are up for comparison to Johnny Mercer, Berlin, Porter, Yip Harburg and the great musical theater writers of the past. Did I forget Stephen Sondheim and Tom Lehrer?
It would be well if S/S's on this side of the pond were to study the songwriting of the Nuevo Cancion in Latin America or the modern songwriting of Africa or India. It would knock the S/S'ers out of the musical box they seem to find themselves in.
Frank Hamilton