Now, once Lowell was gone, once the remaining band members had completed and released Down On The Farm they were off on their own separate ways, until the opportunity to re-form the band came around in 1988.
Now, while you have to acknowledge the fact that Lowell was a major factor in the original outfit, you couldn't blame the surviving members if they found the prospect of session work or a gig in someone else’s band a less appealing prospect than playing the Little Feat catalogue.
Given a stint playing keyboards behind Bob Seger, Art Garfunkel or James Taylor, you're only going to get the solo spotlight once or twice a night. Those guys' shows aren't about keyboard solos, are they? Playing Dixie Chicken, on the other hand, you get a chance to stretch out.
On the other hand, provided the name on the billboard out the front is big enough that backing gig could be rather lucrative. Derek Trucks reputedly used the proceeds of his stint in Clapton's touring band to build a studio in his back yard and recorded Already Free there.
So when you're caught between those backing gigs and hitting the stage to do your own thing you're probably going to be sticking the toe in the water to check the temperature before you dive right in.
That seems to have been the way Little Feat approached things after the 1988 reformation, and eventually, around the time Hughesy joined the Hoy Hoy mailing list IIRC, they'd reached the point where it looked like it might work on a full-time basis.
The likelihood that one or more members of the outfit may have passed, or that one or more members have developed personal issues that mean they're not inclined to make the effort to preserve appearances.