The is one of most unusual questions I have ever seen posted on Flyertalk in the last 20 years.
How about Spainair, Varig, Annette Australia, Shanghai Airlines, and “soon to be in ST” Asiana? These are former *A members, so should UA honor all the past BIS credit to those programs? Some of them went bankrupt but let’s entice their members to fly United by giving them UA BIS for the activities credited to those programs.
How about NW (former PMCO partner), USAir (former UA partner, and at one time Delta and PMUA also had cooperated on codeshare and frequent flyer programs?
Let’s go back a few more years, Pan Am and United had a similar program as Delta/United.
Where does the so called “valuable incentive” begin and…..end?