I know this is going to sound ranty, but it just feels like Android\'s UI components and behaviours are off the wall sometimes.
Consider the following XML:
I felt the same way as you when using the stock RatingBar, so I made my own: SimpleRatingBar.
It features:
android:layout_width: it can be set to wrap_content, match_parent or abritary dp.Here is a preview of it.
You can find it either in jcenter or in Maven Central. So in your build.gradle file just add to your dependencies:
compile 'com.iarcuschin:simpleratingbar:0.1.+'
I hope it's useful.