I'd like to hope that one of the key strengths of Uk manufacturing is the quality and specialist skill. If you want mass produced crap then Britain aint the place.
Whilst I generally don't disagree with your post, I think we have the Japanese to thank for giving us a kick up the backside. Up to the Japanese getting serious in the UK car market, many of our cars (and French and other cars) were rubbish in many respects, the metal rusted too easily, suspension joints were routinely changed at many MOTs, oil seals were almost unnecessary for the difference they made and clutch changes were routine.
The Japanese didn't sit on their bums, relax and gloat like the UK has a tendency to do, they have continued to improve the quality.
Whilst historically the UK management had too little involvement in decisions, I think now as you stated above, they have too much influence compared to their knowledge. Consultants often try and pin down to absolute figures with no engineering experience, so if you tell them it is going to take 35 minutes to change the brakes - they want every brake-change to take 35 minutes with total disregard to reality. This is because they want to transfer responsibility (ie blame, a word they always say doesn't exist!!!) downwards to the little man that can't argue back.
We need management, we need the workforce and we need unions to protect the little man (and sometimes the bigger men). The unions are very weak at the moment, many companies/managers are abusing the workforce. How many times are workers shouted at, sworn at or belittled, this is harassment which is illegal. How many people are working extra time for no pay - which is illegal, there is nothing wrong with good-will and flexibilty, as long as its voluntary and not coerced.