Fostered by the Beer Orders, Pubcos are now the dominant force in beer retailing in the UK. And that revolting phrase, "beer retailing", illustrates exactly what is wrong with them. Anyone who thinks of the industry like that is the last person who should be allowed to do it.
The Big 6 were far from perfect owners but at least they had brewing at the heart of what they did. Even Watney's started to see the light and make proper beer available. But pub companies core business is NOT brewing beer - it's running restaurants or "improving the retail experience for familes" or increasing non-wet sales. Anything, usually, rather than producing, keeping and selling beer.
Put your pint in the hands of people who don't care about it and guess what happens.