At the end of the day the front-end is heavily tied to the visual design of the site. When the visual design changes drastically it makes sense to throw out th

At the end of the day the front-end is heavily tied to the visual design of the site. When the visual design changes drastically it makes sense to throw out the tightly coupled logic with it, and so front-end work is more ephemeral. In this environment there is no incentive to make things last long term. Frameworks can make breaking changes version to version, and websites may change their technology completely in each iteration. It doesn't matter because you will just throw it out in relatively short periods of time.