This has been repeatedly requested for several years at this point. This should not be an issue. Attempting to do a work around to print the rubrics is frustrating and results in either a lot of work or missing information from the rubric.
The only acceptable resort currently is to maintain the online rubric and a text document. However that means making sure that you update the text version anytime you change/modify the CANVAS rubric.
Of course the other option is to not use the rubric feature in CANVAS and stick to the text document.
Either solution defeats the purpose of the LMS and the reason to use CANVAS.
Come on folks this has been asked long enough and frequently enough that you should make it possible through the software.