Sheldon Brown's writing?
Sheldon Brown was a good man, a good cyclist, and he spent an inordinate amount of time writing answers for everybody to questions that every new cyclist has.

In a lot of ways, his answers were pretty dead on. However, like any person with the energy and commitment that Mr. Brown showed with his site, he was very opinionated on a number of issues which are controversial now. 

Because he was also among the first cyclists to use the internet to spread his ideas and knowledge to anyone willing to listen, his ideas are often treated as canonical, even when time and science have moved on.

As with any science, new ideas and equipment overtake the old, and new methodologies, for fitting, for bike construction, and for fitness are tested, and either adopted or discarded.

There are cyclists who adhere to what Mr. Brown said on any topic, regardless of the evidence to the contrary which is available now. But then, there are dogmatics in any religion, and cycling is a religion for many.  And if cycling was a religion, then Mr. Brown was its first, or at least best known, Internet age missionary. 

He deserves respect for his efforts, but not dogmatic adherence to his viewpoints. 

Try his ideas and use what works.  If something doesn't work for you, discard it, and find something that does.  He would be the first to tell you to think for yourself.