Taking the emotion out of this; Mumsnet is self selecting. There were always going to be a a high proportion of ex-teenage mothers who have achieved much and made a success of their experience in all the conventional senses.
However, all evidence (I can quote verbatim if needs be), points towards the fact that the vast majority of very young mothers in the UK are from deprived backgrounds (economically and educationally), and their struggle is perpetuated through the generations. These are the families that struggle to work, to get out of the benefits trap, to avoid the lure of crime. Teenage motherhood should be discouraged.
I too would be defensive if I had had a child when I was very young, and would want to tell my story, but it just can't be denied that the overwhelming evidence is that it is not good for the individual or society. Of course, most sensible people want to support those that need it but this has become a dangerous epidemic in the UK and the cause of many social difficulties.
To continue supporting this situation is exceedingly expensive for the state, and in fact, can't last. Something has to give.
No-one would want to return to a state of shame, but there is a middle ground between shame and costly approbation.
What 15 year old says 'freaking'?