This is unique to BA at Heathrow
You've never been to JFK then!
In comparison flying with Lufthansa to LHR once in the last 3 years have we had a wait for a parking slot at the terminal (I dont believe they have remote parking at LHR).
Yes they do but Lufthansa have a far smaller number of flights a day than BA and therefore can swallow gate delays more easily thus rotate through the same gate.
Ironically we often get a remote stand at Frankfurt as they prioritise Long Haul hulls onto the jetties.
It's all down to an operation called HAC where stands are generally allocated to the arrival time +/- 15 minutes. Long Haul will almost always take stand priority unless the jet is parked on T5A where most of the stands (excepting A19) are only big enough to fit a 767 max.