[AndyN01]

Yes, I absolutely agree.

What would happen if one of "your" tradesmen was told that if their work was sub standard they'd never work on any of the sites again? And, of course, there's a difference between can't be bothered to do it properly and unable to do it properly.

But what do someone do if they have no knowledge of what they're paying another person to do?

How about perhaps needing some legal advice?

We can't possibly be aware of all the finer details of everything and the "correct/best" way of tackling any given job. And, for me, that's where a professional earns their money because they do (or should).

I'm sure we all know very intelligent, competent, highly skilled people in their own field who are woefully inept at other things. I know a mathematician who is unbelievable with figures but their DIY skills are none existent. I'd happily pay them to work out some complex maths problem that I wouldn't know where to start but give them a screwdriver or a drill and you'll be heading to A&E.

In the end you pays your money & takes your choice.