Hi Weeves
I am currently studying with the OU, and will try to answer your question.
The OU was founded back in the 60's [I think] with the specific intention of allowing people who had not got good exam grades at school to study a degree and get better job prospects.
At that time University was seen as pretty elitist, and was not an option open to kids from "working class" families unless they were very lucky. The OU tried to overcome this and tended to attract older people, who had some work experience and wished to improve their lot in life [or just study something that was of interest to them]
It is, as far as I know [and I may be wrong about this] the only triple accredited university in the World that does not require students to have any previous formal qualifications,
From my own point of view, I am currently studying for a degree in Business Management, as is my son [I am 53, he is 27] I appreciate that it may seem unfair after you have worked hard to gain A levels etc that my son and I can get the same degree qualification without that hard groundwork. But, you need to be massively committed to the OU, you normally do it as a part time course, so it takes 6 years to get a degree, normally whilst holding down a job at the same time. You do not have the support of other students and tutors in the way that I understand you do at a traditional "brick" uni.
When independently assessed, the degree quality normally scores very high, although some employers look down on it this is generally through snobbery, and many employers look at the commitment required to get an OU degree as a major plus in your favour.
Oh and by the way, even though I got very few exams at school, I could spell mediocre by the time I left [Sorry I could not resist]