cyccommute 

Never read the book. But I do have 25+ years experience building wheels and 30+ years experience of riding and observing wheels. I've had my share of failed wheels, failed spokes and failed rims. A rim that fails isn't a failed wheel, unless you can't find a rim with the same effective rim diameter. It is relatively easy to detension an existing rim, swap the spokes to a new rim and retension the wheel to have a perfectly serviceable wheel. I've done it many, many times... such as, for example, in the case of a dented rim like ericthered's. If the rim were the weakest link in the wheel system, a broken rim should be the end of the wheel. Even pulling a spoke through the rim doesn't mean that the wheel is dead.

However, a broken spoke is usually indicative of something much more ominous and systemic. Two broken spokes is cause for concern and breaking more than 2 means that you should quite riding the wheel and rebuild it with new spokes and a better technique.

I ride narrow lightweight rims on mountain bikes and road bikes. I'm never concerned that a lightweight rim might fail. I don't, however, ride wheels with low spoke counts because I know what happens to low spoke count wheels when used for heavy riders.