I know it's complicated but
I know it's complicated but it would be helpful if Kelly's article showed some evidence of clue about the different roles played in this picture by the allegedly independent parts of BT.
BT Openreach: provider of connection between punter and BTwholesale kit in the exchange (or indeed other providers' kit in the exchange, but this picture relates to BTwholesale).
BT Wholesale: historically incompetent provider of connectivity between exchange kit and ISP kit, traditionally using badly designed and/or undersized networks and charging outrageous wholesale prices to "smaller" ISPs, whilst offering a different product family to parent BT Retail.
BT Retail: overpriced and underperforming broadband provider, default choice of the ill-informed.
BT Sheffield: Plusnet, a diversionary "smaller ISP" which allows BT to undercut other BTwholesale-based ISPs whilst still raking in the money from the ill-informed on BT-branded tariffs and while Ofcon stand idly by.