You may be interested in this similar question a month ago:
I'm CB's consultant accountant, with my own practice, and was actually brought into CB originally to help with developing Final Accounts and Kevin is absolutely right, it would have been in my best interests as an accountant to be able to do my clients' accounts where their books sat rather than, as I do at the moment, export the data into specialist, expensive software.
As Kevin says, there was a huge amount of development time involved in getting the original version to 98% only to then look at building or buying in a tax module to enable the full range of possible tax issues and submissions to HMRC. This was on track but then HMRC's digital tax plans loomed on the horizon with the distinct possibility that HMRC will not require final accounts in a few years.
When added to the fact that the Government's own facilities were perfectly adequate (and free) for micro businesses, the case for in-house Final Accounts was lost and so the decision was made to spend the time on far more important core development that would be more beneficial to all users.
Personally, having invested a couple of years into it, I too have an element of regret in it not coming to fruition, however, these days nothing stands still for long in compliance & IT and this is another casualty I'm afraid.
All the best