i noticed the same problem with the use of the term proprietary because that simply means non-standard. there is plenty of non-standard Free Software. and there is also plenty of commercially sold Free Software (RHEL for example)
the only term that i am aware of that really works is non-free.
"commercial software" has a well-used and generally accepted definition, regardless of how the DOD procurement rules define the term.
as more and more companies sell FOSS licensed software, that definition is going to change. commercial software as the opposite of Free Software worked as long as the majority of Free Software products were generally free as in beverage in addition to having a free license. "Commercial Open Source" is a thing. https://en.wikipedia.org/wiki/Commercial_open_source_applica...
Just a side-note about the distinctions between open-source, free software, and commercial software. The US government considers any software that has a license and is available to the public “commercial”. So all GNU software in their view is commercial. It’s not a legal distinction of whether money is charged, it’s whether the software has a license and is public.
U.S. law governing federal procurement (U.S. Code Title 41, Chapter 7, Section 403) defines "commercial item" as including "Any item, other than real property, that is of a type customarily used by the general public or by non-governmental entities for purposes other than governmental purposes (i.e., it has some non-government use), and (i) Has been sold, leased, or licensed to the general public; or (ii) Has been offered for sale, lease, or license to the general public ...".
https://dodcio.defense.gov/open-source-software-faq/#Q:_Is_o...