MV* is the prevailing architectural pattern of frontend JavaScript applications. We're referring to this as MV* because there's a number of accepted variations on the pattern, each of which have models and views as core concepts. For our discussions in this book, they can all be considered the same style of JavaScript architecture.
MV* didn't gain traction in the development community because it's a terrible set of patterns. No, MV* is popular because it works. Although Flux can be thought of as a sort of MV* replacement, there's no need to go out and tear apart a working application.
There's no such thing as a perfect architecture, and Flux is by no means immune to this fact. The goal of this section isn't to downplay MV* and all the things it does well, but rather to look at some of the MV* weaknesses and see how Flux steps in and improves the situation.