sorry Davros, I don't agree, though accept that this may be the case for you personally. Part of the skill of being a professional is knowing when a parent is ready to hear a diagnosis. I am also a very direct person and would prefer information up front, but this doesn't apply to everyone.
As a newly qualified therapist I made the mistake of thinking that everyone wanted to hear a diagnosis as soon as it is made, but I soon learnt this wasn't the case, either through immediate reaction or through feedback. As I progressed professionally I learnt to read the signs more carefully and listen to what the parent was saying more carefully.
I recently handled a case of a lady who had been told her son was on the autistic spectrum 12 months ago. She had refused to accept the diagnosis, fought the professionals involved and generally suffered a lot of heartache. When she came to see me, we discussed the autistic continuum in greater depth (I probably had more time to do this than anyone else she had seen) and she seemed to accept the diagnosis for the first time. She later told me that her coming to accept this was a two fold process - firstly she hadn't been ready to hear the diagnosis twelve months ago, and secondly she didn't feel it had been handled well at the time and she hadn't been given all the information or time to discuss.
I strongly think that, even if the paediatrician had spent all day with this lady twelve months ago, handled it beautifully, she would not have been ready to accept the diagnosis at that point. It might equally not have taken her twelve months to come to that point, but that was how it was for her.
People are so diverse and I hope that some of us professionals allow for that when we are dealing with parents.
Of course, it goes without saying that any parent who asked me directly for a diagnosis would be given a very honest answer - it's their information, they own it, not me, so I'm not suggesting that information should be witheld in some sort of patronising way.