It is true that by enforcing that value movement have both a source and a target, we make it possible to add a useful checksum to the system. But I believe this is a side benefit to the more fundamental trait of requiring all value flow to record both sides, in order to capture the cause for each effect.
I agree with your general perspective though: technology has afforded us new and different tools, and thus we should be open to new data models for accounting. I don't agree with other commenters that we should tread lightly in trying to decipher another field, nor do I agree with the view that the field of Accounting would have found a better way by now if there were one. Accountants are rarely, if ever, experts in CS or software engineering; likewise software developers rarely have depth in accounting.
Source: just my opinions. I've been running an accounting software startup for 5 years.