You are quite right.
But being of old age, with slow-walking high-heel wifey, plus heavy hand luggage (with laptop on my shoulder and pulling heavy attache case), zigzagging through crowd an a longer trek is an unwelcome addition to a long voyage. A voyage that started in a ride to another airport, with a not-so-good night sleep and too much wine, and the prospect of sampling another final airport.

I agree that this is a minor inconvenience, especially seen from a cattle class perspective. But the decision to travel in F is hardly rational. You do it for all these little pluses that make a flight very enjoyable rather than a pain. And BA keeps piling up enhancements that makes it really poor relative to other F products.
The F wing is a positive enhancement for LHR-originating pax but a negative enhancement for transit pax.