They want to be all glum as Shostakovich; and this is a little too cheerfully tuneful for them that it reaffirms the fact that life won't ever be truly daft and empty, if only they just let in a little light every now and then?
Perhaps it's the difficulty of getting the supplementary players for a quartet. It is well known by amateurs. How often are the Brahms sextets played, after all?
Correct. It's very well known to (and loved by) us amateurs, but (rather like the marvellous double bass quintet) is not played as often as any of us would like.
