It's kinda tricky naming names.
For the most part it's simply 'not the done thing' within the trade - not out of any sense of protectionism, but perhaps because it might lead to people routinely criticising services in an effort to scupper the competiton.
And you'd have to be completely certain of the circumstances, or lawsuits might be forthcoming.
There are exceptions, however - such as when work is so incredibly and obviously bad that there's absolutely no doubt who's responsible for it.
It is, however, fine for customers to voice their complaints - hence the rise in popularity of sites like Tripadvisor etc.
And I have to say, if I'd spent £360 on repairs that didn't work, I'd be very quick to name names.