It really bothers me the way the UA attendants enforce the seat belt. Half the time the seatbelt sign is on when there are no bumps. Half the time it's 30 minutes on the runway, then 20 minutes after takeoff no sign of a beep for the seatbelt sign.
It gets ridiculous.

It's one thing to recommend people stay seated, it's another to admonish a passenger for going to the bathroom.

It's not quite like this, IME, on other carriers. FAs will often 'remind' pax of seatbelt sign, but not demand that they go back to their seat