I'm in complete agreement with you, but I think we wouldn't need to rely on personal interpretations and recommended practices if the SA licenses stated clearly something akin to:

If a copy or a derivative work of the licensed material is to be included in a piece of software under the General Public License or other strong copyleft license, then it must be licensed under that license for compliance.

I don't speak legalese, so I'm sure that text is full of holes and possible misinterpretations, but surely a group of experts could come up with something legally viable in that spirit.