Why did The Righteous Brothers quit the 1964 Beatles' tour?

According to Bobby; Rolling Stones, Beatles, we gave them all the break they were looking for. All they needed was a good opening act and we went out there and performed as well as we could ..over fifteen thousand kids chanting "we want the Beatles" After the last time they chanted that we went to the manager Brian Epstein...It just happened to be the same time Shingdig was starting to work on a new show and also their manager Brian Epstein.

righteousbrothers.com/interview.htm no longer exists

Early in their careers, The Righteous Brothers, Bill Medley and Bobby Hatfield, were the opening act for the 1964 Beatles tour. Having never heard of The Righteous Brothers, the Beatles fans screamed "We want the Beatles" drowning out their sets. Medley and Hatfield decided their careers would be better served if they quit touring and accept an offer from the new TV show "Shindig." The national exposure gave them a showcase for their own songs. "Little Latin Lupe Lu" (written by Bill Medley) was their first hit, followed by "You're my Soul and My Inspiration (written by Bill Medley and Bobby Hatfield.)
http://www.songfacts.com/facts-the_righteous_brothers.php

According to George Harrison:

The Righteous Brothers were on stage singing You've Lost That Loving Feeling, when we came hovering over in this sodding big Chinook. All the people were up in the stands, pointing up to the sky, screaming and shouting, paying not a blind bit of notice to The Righteous Brothers - which pissed them off a little. In fact, they got so pissed off that they decided to leave the tour. Righteous indignation.

https://www.beatlesbible.com/1964/09/02/live-convention-hall-philadelphia/