Yeah, I heard about that, but never heard anything about why.
I recently watched the Blu-ray Jethro Tull Live at Montreux and it was amazing. I was expecting it to be an aging band playing all their hits, some a bit more slowly than originally, and a few with some "variations" to them that have crept in over the years to keep things fresh for the band members themselves, because that's usually what you get with a recent concert vid from a band that's been around for 40 years.
But I very very pleasantly surprised. Ian and Martin were the only originals, but they're the core of the band, as far as I'm concerned. It would've been nice to have Hammond-Hammond-Hammond there, but the keyboard guy they had was great, and was hamming it up on stage with the rest of them. Performances were solid, nothing slowed down, nothing watered down, and the selection of tunes was great. A couple of sweet instrumentals, some great album cuts, and other than "Aqualung" (pretty much required) they almost seemed to be avoiding the hit parade, which is fine. I always preferred their proggy album stuff anyway.
I have everything from This Was up through J-Tull.com. Their sound has changed a lot over the years, which is fine, but I think I lost interest after J-Tull.com. But I stuck with them from the early blues-folk stuff through the prog years and into the later stuff, whatever you might want to call it. Every album has merit, at least a handful of great songs if not the entire album, I just moved on I guess.