@stuartk There is nothing wrong with improvisation per se.
But necessarily if a a large percentage of performances are mainly improvisational. performers will be unable to maintain a high standard for many of them. Absent the ones that could be classed as 'poor', many will tend to be similar and continue for lengthy periods along similar lines. I think this is what FZ meant by 'noodling'. I might call it 'being on the road a while but not getting far' or, perhaps, 'taking the long way around'. Some might find too much of this tedious.
As in all things, quality is what counts.