A lot of people use Ubuntu for scientific computing.
Can we have a tag for it?
First of all, if you were going to go this route, I would recommend using the same
data-science terminology that Stack Overflow uses. They may not be identical terms, but I think the software that you reference tends to lean towards "data science".
And there might be a case for there being unique
data-science questions here on AU, but the vast majority of those in your searches certainly don't seem to qualify, IMHO. Just looking through the octave questions, for instance, the vast (vast, vast) majority are simply installation issues of one sort or another.
Honestly, I haven't found a single question yet in any of those tags that I would consider data-science and/or scientific-computing. Not that I've exhausted, but I've skimmed through at least 60 questions in those tags without coming across a great candidate.
This tag seems unnecessarily vague.
It's not even a single class of software (eg calculator), it barely an intention and broadly speaking, it would probably only serve as an umbrella around several tags which are otherwise more specifically tagged because they're about that software, not the intention.
I'm probably not being imaginative enough but I don't see who this tag would help.