Loyal BA (BOAC before that) customer after leaving PanAm as an employee and losing that free option for travel. Introduced to BA/BOAC by a gentleman caller who worked for BA/BOAC, who took me on several trips gratis back then on "his" airline.
Given the extraordinary and famous training and customer service PanAm required back then, it was a pretty high bar and BA/BOAC not only reached it in my experience but often exceeded PanAm.
I also liked traveling on holidays away from my own airline after leaving soas not to run into folks I knew and then the flight became a non-private sort of event with people wanting to come by and chat and do the old complaining about management, etc. LOL
After a few trips on my own on BA/BOAC I just stayed with them. They had good fares and good flight times from my US portal city. It's lost for me in the mists of time but eventually there was a frequent flyer program and began totting up miles on that, so just stayed on.
Tried Virgin a few times due to necessity rather than choice. It was okay. But that was before there was a premium economy on Virgin or a WT+ and CW choice on BA.
But by then had many miles on BA, and wouldn't have switched alliegences. And also Virgin has only one flight a day from my airport. So it was never going to be a contender.
Roll on BA.
p.s. Now if BA would just begin to offer a couple of child free premium cabin flights....(!!!) Sorry....