For me that's the single lowest point of the film.
The next lowest being the "Oops, we got hit one too many times, I guess," destruction of the E-D.
The third lowest being the sheer ineptitude required to let an officer who they know has been compromised before...and by the same piece of hardware he's currently wearing, no less...go right back into an area with sensitive information...and apparently never detecting the fact that he's broadcasting on KTV.
Those are all low points.
But for me, the lowest point is... well, I guess it's not just one
It's just the entire usage of the silly "nexus" idea. Picard has this amazing opportunity to use the Nexus to go anywhere and anyplace in time(overpowered and dumb plot device to begin with...) and they pick 10 minutes before Soren launches his rocket?
This classic youtube edit pointed it out best: