ewee disinformation?! Sorry but it is what I have experienced going through the UCAS process with DD a couple of years ago, and discussing the admissions process with my colleagues at university in London and an Oxford College ( I'm a postgrad student) and years on the milk round recruiting graduates for a management training scheme. DDs year were prepared for the Oxbridge process with a warning that even the students the school regarded as having the best chance of success might not get in. One of the reasons, aside from them having a bad day was that since you are interviewed by the tutors who will teach you, they will choose the pupils they want to teach. Every year there are surprises, bpoth in terms of who doesn't get in and who doesn't, and as it gets ever more competitive there are more surprizes. And so it proved.
The tutors who interview applicants find that with record numbers applying globally they have so many amazing students it is getting ever harder for them to distinguish who gets offers and who doesn't. Cambridge wouldn't claim that they definitively recruit only the brightest, they deliberately advise "While academic strength is a pre-requisite, it does not guarantee acceptance. We are looking for well-motivated students who are well matched for the courses they have chosen." That is part of the reason Cambridge run the pool, where students rejected by colleges but judged to be of Cambridge standard are offered around the other colleges, so they get another chance, though most still don't get picked up. Cambridge actually publish the detailed statistics on number of applicants and offers by college, and by subject area that demonstrate there is a marked difference in your chances of success between courses and colleges. Of course the colleges that were not popular one year may suddenly become more popular as a result of the statistics being published and students applying strategically! This article gives a very interesting insight into the process. So I think describing the chances of your bright child getting in as a lottery isn't overstating it!
And you only have to look at the subject tables for most of the respected league tables, whether they are on based on research or teaching to know that Oxford and Cambridge do not take the top 2 places for every subject.
There have always been shocks and surprises in the university admissions process, my friend got 5 rejections but ended up at Oxford ?? years ago but now, with the process being so much more competitive, parents cannot assume that just because their child is bright, however spectacularly, and they have got them into the "right school" that they are automatically en route for Oxbridge, especially if their child is still only in Year 9. LEH don't start to talk about Oxbridge potential until the end of Lower Sixth.
Perhaps the disinformation is in your comments on what employers are looking for? Firstly it varies hugely according to what sort of applicants they are seeking and for what. My comment about the BBC was based on the experience of an Oxford graduate who not only has a first but was successful in beating extensive competition to get several internships in broadcast jounalism and has spent the last two years building up an amazing CV and getting through tough telephone interviews to testing interview processes for countless jobs but still not even a sniff of success. She is now resigned to a career in marketing / PR. She is quite sure it is because, as she has been informally advised by her contacts in the media, the pressure on the media, especially the BBC, to employ a representative cross section of society mean her private school and Oxbridge education count against her. The above mentioned friend walked out of Oxford into a graduate job in advertising, now on the board she admits were she applying now she wouldn't stand a chance, they are looking for relevent accomplishments, interesting life experiences as well as academic success and set potential applicants a whole set of work related challenges, putting together 7 videos according to a set of briefs just to get an unpaid six week internship that might lead to a job. The successful applicants come from all sorts of backgrounds and unis. I have yet to hear of a graduate recruiter who bothered with the milk round only visiting Oxford and Cambridge! For obvious reasons you do get some employers who only do London unis but if they are going to put together a roadshow in the first place you might as well tout at a few of the best! The most limited I have encountered was a City Law firm who off the record admitted they only considered applicants from six unis and limited their acticities to LSE, UCL, Durham, Bristol and Warwick. And if you want to get into banking then Bath punches well above it's weight in terms of the success rate of it's graduates (because they have developed relationships and designed their courses to give banks like Goldman Sachs and UBS the graduates they are looking for). This is all reflected in the graduate employment tables in which whilst Cambridge is second only to Imperial with an 82% employment rate, Oxford langushes behind LSE, UCL, KCL, Bath, Bristol, Durham, Aston, Glasgow, Cardiff and Warwick (in that order) with 73%.