In defence of my fellow tutors, it is quite hard to tell parents the truth in a way they find acceptable. With some, even the smallest criticism of the child, leads to a very defensive response where they go into long explanations of why the child is underperforming, a small part of which may be applicable. If you're too subtle in hinting at likely failure, it just flies over heads. If you're too blunt, it upsets people and usually for no good reason as the parent will probably soldier on with you, although now your relationship will be a little sour...and the job is hard enough without that.
And you may also be wrong in your judgement. I have had at least 3 students who gained entry against all expectation: mine, their parents and their schools. I have had a student drop out after I have been honest about her chances within 3 months of beginning tuition (she had no interest, hated tuition and was doing almost no homework), only for her to decide at a later point she wanted a grammar school place and was prepared to work exceedingly hard throughout the summer with her parents; as far as the parents were concerned, I had been wrong in my initial assessment although I would argue I was right in my claim that, without the necessary application, she would not make grammar school.
Even when you know a child is going to need a special effort (certainly more than you can do in 1 hour a week) and you go to the trouble of giving parents a package of extra work, some clearly resent it, feeling they are paying you to get their child into grammar so why should they have to do anything.
I think if a tutor is talking about 12+ or says things such as 'well, none of this will be wasted and will help with secondary school, anyway', you can probably assume that they are trying to be subtle rather than say outright they think a pass is unlikely.
FM I'm sure you are right it must be very difficult, but to tell someone 'you child isn't up to it' only when they cancel the booking? Churlish at best surely?