That's fair, but I think if it works in 90% of cases that's a huge win. And it seems like it'd be pretty easy to close that gap (with multiple solution methods).
100% agree. A simple "here's what we think you owe" postcard for 90% of people and a "we think you might have unreported income based on your bank transactions - please fill out a full 1040" for the other 10% would be a massive improvement over today's system.
Right now the system is that everyone gets a "we think you might have unreported income" and I don't see any problem with that.
What I don't understand is why we can't have the IRS running their own tax prep website. The government seems to be capable of running other websites just fine.