It is a competition, for routes. Otherwise why would you be so worried about losing long range if your earnings are guaranteed? It's BA's business, they should be able to run it as they see fit.
For example, you are building an extension at home. The builders you have used before give you a quote for £20,000 and it will take 10 weeks. A new outfit comes along and says it will build the same extension, at the same quality, for £10,000 and in 6 weeks.
Would you go with the builders you know if the extension was going to be the same, and worse still, would you like it if someone insisted you use them, despite the extra cost to you?