4.2.2 was removed in the 2008 edition. I have not researched why this was done, but it was probably viewed as redundant.
The short explanation is that coordinating values between various codes and standards is difficult and may not always be appropriate. The committees at ACI are trying to eliminate overlap where they can. You will see changes to the next edition of 318 (that's an understatement), including where many such overlaps and redundancies are being removed and users are referred to another standard.
We may have allowed the complexity of these codes to become detrimental to designers and builders, which is why many of us in the industry are pushing for simplifying codes and standards. The International Code Council committees have a mantra "Minimum Code" when presented with the Next Big Thing. The goal of that is to only mandate minimum requirements, not best practices. ACI Committee 318 should be implementing code minimums in 318, and referring users to other standards for guidance toward best practices. However, this can create conflict - remember that 318 is the code, and the rest are just good information unless cited in 318 as mandatory. As a designer, you need to know about both and use your judgement about when to apply more than minimums.
