Waiting for a gate was even worse in the days when BA operated into T4. A half hour wait was not uncommon. It may have been better to have more remote parking.
JFK T7 (the BA terminal) I think only has five wide bodied gates (3-6 & 9) and that's not really enough capacity. If you arrive just before 19:00 local you are always waiting for someone to push from a stand. (Surely not why the cheapest fare is normally on a departure from LHR around 16:00.)
If you have nothing better to do listen to the JFK Company Channels in the archives of liveatc.net on a bad day (yes it is legal). As an aside the US has a rule that fines (heavily) airlines if passengers cannot alight for an aircraft after three hours on the ground (four for international flights). No one likes being held hostage but it does cause some grey hairs amongst ground staff.
ATC Audio Archives | LiveATC.net
Listening to: KJFK Company Channels | New York, New York, United States | LiveATC.net