The problem is that it is super easy to modify a Gradle build scripts, but also super hard to get it right (e.g. understanding of configuration vs. execution phase, concept of configurations, task dependencies). As long as you don't touch the build script, Gradle is superior to Maven in _so_ many ways.
Yes, it has what I would describe as a cliff learning curve and I think that is it's biggest drawback. One understands Gradle or one doesn't and that is pretty far from ideal.
