[meinersbur]

Both claims are incorrect.

LaTeX would rather produce a bad document if it cannot produce a good one. Example: overfull hbox. A designer is still required who creates the documentclass, it is just that LaTeX comes with some predefined ones intended for scientific publishing.

HTML+CSS require pixel-perfect rendering. Example: ACID2 test. While it might have been the idea of plain HTML at some point (<em> instead of <i>), control has never been taken away from the author thanks to CSS.

[wtallis]

You're badly mischaracterizing tests like ACID2. The test definition includes a long list of things that invalidate the test, including things like changing the zoom level. So it's wrong to construe that test as requiring pixel-perfect rendering when it explicitly doesn't cover exactly the kind of user agent controls I'm talking about.

Your comments about LaTeX do not seem to contradict anything I said.