The economics of software are important and in no way would I want McNeel to divert resources that could otherwise be used to grow their user base or improve their software so that they could do a full port to Linux, however at the moment this thread is the top result that I get when I Google for “Rhino on Linux”:
This is a great user-submitted thread from 3 years ago. McNeel does NOT need to divert massive amounts of development resources from Rhino to a full Linux port, but they could put some nominal effort into helping start the process of getting it to run and providing scripts for users to get some basic support. Even a blog-post style page with disclaimers about lack of support and a comment section so users are able submit tips to a single, unified resource would go a long way in helping to create a kernel from which a Rhino on Linux community could form.
Completely ignoring the nascent Rhino Linux community clearly discourages some amount of existing Rhino users and forces them to look for alternatives. Even Autodesk has a Fusion 360 on Linux option (through the browser). A simple rule of business is that it is much less expensive to retain existing customers than to have to acquire new customers or or reacquire customers that have left.
If these arguments are recurring enough to have been “heard before” then there is some demand.