Actually I hardly fly BA at all - mainly Star but lately I have done a lot of Sky Team. I often book cheap economy tickets and Sky give full miles whereas One World give 25% - 50%. Also it was a piece of cake to get to Silver on Sky and I am almost at Gold, again mainly on cheapo eceonomy tickets, although some have been business. And cos hardly anybody flies Sky Team, if you get Silver or Gold it feels very elite compared to, say, BA, where T1 LHR is crawling with Gold BA's. And Tier bonus is awarded on all tickets no matter what class/price, although the Star basis of giving a Tier bonus on a business fare is more generous.

But your point that the airlines in Sky are second rate compared to OW and *A cannot be disputed - however the scheme itself is reasonable and given that on many routes I fly I have no choice but Sky then I am thankful for that.