dimensionsAndMetrics should just pass the object as expected

[pbrain19]

I am working with a huge app that has some analytics in. When trying to use the setUserProperties the source reveals that all properties are ignored if they do not contain the word metric or dimension. This restriction needs to be removed as google maps does not have such restrictions and it interferes with naming conventions a user may want in their analytics. So my question is why there is a need for dimensionsAndMetrics method?