This is something weird I’ve seen in ERPNext and rapidly becomes a problem when you want to reconcile.
For example:
I have several transactions I want to register against a Bank Account. In Venezuela, for example, a debit is accompanied with to more debits: bank commission and debit tax. ERPNext automatically combines all debits/credits with the same account and this makes difficult to reconcile de bank statement as this operation were registered separately in the bank.
My point is that this shouldn’t be de the default behavior at least. It could be an option in Account Settings.
I guess, for Journal Entries, users expect ledger entries to exactly match the accounts and amounts specified. We can add an option in JE to toggle this behaviour.