Having been using jenkins several times since it was Hudson, as well as Bamboo, travis-ci, python buildbot, and TeamCity, Jenkins is a loser from my perspective. Not worth becoming invested in. Its simply too difficult to use by a laymen developer or sysadmin when accommodating complex buildchains, which only grow more complex over time in most software businesses. If you're going to program your CI with a web admini…
Yes, software is harder to manage (long-term) when the primary interface is a GUI. However, the new Jenkins 2.0 fixes many of the issues you've described. Build pipelines are a major new feature, as well as the integration of a "Jenkinsfile" which allows configuration of jobs via a proprietary DSL.
This makes no sense to me. Only how my project is built should be checked into the project's repo, not the whole CI/CD deployment pipeline! If I start deploying to Azure instead of AWS I need to commit that change to my project? It's nonsense.