I am not sure that the "higher status paradoxically reduces the value of Avios" statement holds true, or maybe I am just misunderstanding it. Higher status holders earn more Avios for a given journey and hence the cost per Avios earned is lower. However, when it comes to redeeming Avios the cost is identical irrespective of what status you hold. When it comes to considering the value of Avios I'd be looking at the number of Avios required for a specific flight, not what it cost to acquire those Avios in the first place.