To me, it's actually kinda sad how that worked out, although it's a messy, complicated situation and I don't exactly blame Ian Anderson for it.
I mean, the band name Jethro Tull is inextricably linked to Ian Anderson. Many people literally thought Ian Anderson was Jethro Tull, in the sense that the guy up there with the flute is named Jethro Tull. So he made a solo album, a statement of who and what he was outside of Jethro Tull, but it ended up being a Jethro Tull album anyway, simultaneously destroying the old band and further blurring the line between Ian Anderson and Jethro Tull, if it even existed anymore at that point. As a casual fan at the time, I basically figured Jethro Tull is whoever Ian Anderson says it is, just as Robert Fripp decides if the band is called King Crimson or not. There are other examples, where there is a band identity but specific individuals say who the band is.
Ian has conceded the point, probably did a while ago. Jethro Tull is whoever Ian says it is. So instead of being bummed that there's apparently no distinction to most people, he's embraced the concept that he has the final say. Unexpected upside?
Vaguely relevant non-sequitor: In 1975, Leonard Nimoy was so tired of being typecast as Mr. Spock that he wrote a book called I Am Not Spock. Pretty much says it all. In 1995, I Am Spock, also by Leonard Nimoy, was published. Okay now that says it all. He has embraced it and come to terms with it.