I think there are perfectly valid arguments for both behaviours. However, in the past it has not mattered which style of allocation was used (except that this now explains the odd values I was seeing in the statistics - see the other post!). Only now, with the highlighting of allocations and the associated warning - which I generally consider a good idea - does a problem occur.
For those of us that use categories and participants together and who wish to continue to do so, a simple fix would be a preference box we could untick that stops participants being taken into consideration during allocation calculations and percentages.
Long term I agree that some special additions to iCompta would massively help people allocate to both participants and categories. Specifically, the ability to allocate to a category on a per-participant basis (and then see split totals / statistics per participant) would be fantastic.
While business finances most often only deal with a single owner and have payees and payers, home finances is much more about multiple participants: students sharing at university, joint holiday funds, household finances with separate budgets for husband and wife. There are many occasions where the participants are equal in status so the concept of loaning money doesn't really fit but where there is also a need or want to categorise the money allocated to a participant. Actually, the categorisation is most useful when linked to budgets and being able to track budgets for multiple participants separately is really useful. The ability to create 'fake' participants is also massively useful - I used a fake participant for tracking wedding-related expenses and this allowed me to see where wedding fund money was distributed across multiple real-world accounts, how spending was matching against budgeted areas such as flowers, dress, etc. and how much the whole affair was costing.
To me, categories help with budgets while participants are more to do with ownership (by either real people or fake event-focused pools of money) and tracking both is extremely useful, allowing me to move money around between accounts without getting into a mess
The participant capabilities of iCompta are already very strong and I consider them a massive point in favour of the software over and above other packages. If you wish to truly separate iCompta from the competition - especially now it is a shareware application - building on the multi-participant foundation would be a very good step.