Piecing libraries together to quickly produce a result can be one thing; building maintainable applications and test suites around them however, can be quite another.
The former approach leads in spending endless hours of frustration and mismanagement, while the latter in the freedom or mastery of “bending” tools and abstractions to serve business requirements in a precise way, an ability that can be discerned in skilled engineers.
While the quick approach can be our only choice in certain situations, one will eventually need to incorporate testing in the development process, sooner or later, if there's any hope of achieving anything beyond a mere prototype.