Gertrude Stein and Claudia Rankine

In reading Gertrude Stein and Claudia Rankine, I really wonder what the two have in common (if anything). Are they doing a similar thing, just in two different ways? Or is there message just as different as their style?
Claudia Rankine's Citizen is poetic social commentary on what it means to be a black citizen of the United States. She has poetic style, for sure, but she also has a clear message. Her poems are normally easy to understand, even if they are disturbing to read. But there is not much abstractness to her. She also prefers to insert paintings or photographs into the text, rather than forming an image out of words.
Gertrude Stein in her Tender Buttons is quite the opposite. She always seems to be forming an image out of words, and it is rarely clear what she is saying (if anything). She doesn't have to be saying anything, that's fine, but I wonder if she is trying to say something that I'm missing. Her poetry has been likened to a cubist painting, and I would certainly agree with that assessment. In both Stein and a cubist painting, you never really know what it means, but sometimes you just enjoy it.
My theory for the core of the difference between Stein and Rankine is two-fold. Firstly, they are two very different people in very different contexts, and so they produce very different poetry--simple as that. Secondly, if Stein does have something she is trying to say, I don't think she is very concerned with the reader getting it. Rankine, on the other hand, is very much concerned with being heard. Her message is too important and has too many implications for her to conceal it behind vague abstractions.
Although I prefer the upfront and unveiled style of Ranking, those assessment shouldn't come as critiques to either writer. Stein has her virtue and Rankine has her virtue--their respective virtues are just very different.