I reckon your frustration and anticipation is well warranted. While I think the process of swapping out is a logistical necessity on some occasions, there still should be some form of reimbursement for the poor passenger. Many of us don't fly for work - we fly for fun. How many people are there planning special holiday flights and choose Virgin over Qantas for a particular sector, assuming it will be "The Business"?
Creating and paying for an itinerary based on the information provided at the time of booking SHOULD also underwrite an assurance that, in the event of a change in metal - a points compensation or monetary refund is pending.
I am a small trade business owner/operator who relies heavily on the 80/20% philosophy. (80% of my income comes from 20% of my customers). And if I sold one thing and offered another - I'd have very few loyal clients left.