The problem was not the use of best practices per se, but the uncritical use of these practices. For example, it's good to use design patterns, but not every pattern is appropriate to every situation. We got to a point where it might take a full day to make a change to a table, and then make the corresponding changes to all the various repositories and entities. Similarly, it's good to use the latest technologies, but using beta versions of unpublished frameworks was a bit over the top, both because documentation was scarce and because they were still buggy.