I think my biggest problem with the front-end that makes it unenjoyable is that the community seems to have ADHD. Every other month, there is some new tool that comes out that doesn't necessarily do anything all that different, but it's just a twist on some functionality covered by some old tool. It's hard to put builds together because there's always some new tools that you have to spend time learning. You have browserify and now webpack for bringing in external modules. You have like 3 different module systems, aka commonJS, AMD, and ES6 modules which is a mix of the two. You had to learn Angular before and now Angular 2, which is completely different, is on the way, and you got React.js, which you have to use with a ton of other libraries.
I really wish developers on the front end would just start standardizing some tools. It's getting annoying that every time a new developer has an idea, they are releasing some framework or library.