Too Long; Didn't Read
If you are new to rails and trying to decide whether or not to learn rails let me make this easy for you. It depends on what you want to achieve by learning this technology. Learning rails can help you build your project, get a job or just get started with back-end development. But if you are pretty good in some other backend technology you could use the time in getting better at it. Django is an amazing alternative or you can never go wrong with JS or any of JS-based frameworks.