Well, the problem has been identified or at least highlighted by our Editor: there needs to be a free and open standard for defining the data required to process tax returns.
The solution is of course to start a project. I'm not volunteering :-) But there is quite a large community of business and accounting packages developing. Maybe now they've read it here, they can get together and produce a sane and general specification. No doubt it will be better than QuickBooks' output. Somebody will start to use it eventually - either an existing tax accountant's program or a free replacement.