As an example if I am writing a fairly small (<50kloc) user facing internal web application where I can work directly with my users, and I'm going to stick around a while, and I don't know the domain real well I'll usually spend 20% of the effort on requirements, 10% of the effort on design, 10% formal requirements and design reviews, 10% on integration/feature tests, 5% prototyping, 5% doco, and the remaining 40% of time on dev. This means I do no code review and have no unit tests. It works very well in this context and allows rapid delivery of business value.

If you take this same configuration and apply it to framework code you are releasing to other internal dev teams then it wouldn't work (and they would hate you).