They very likely do. On the M: and Z: drive.
As far as I can see this is just IT saying “if you stored your data somewhere you shouldn’t have, it’s now gone”.
But of course they can’t say that, so instead they have to help people recover from their mistake.
Or maybe the mistake was thinking people would actually do what you told them instead of whatever was more convenient.
You're assuming people are aware of where they — or their niche specialty software packages — store their data. I'm not even sure I'd know where e.g. some biotech-DNA-analysis-package stores its data.
Recently I've been given incredible abuse by my ex who accused me I took her external HDD when I moved out. I actually considered I did and scoured all my boxes and belongings and even invited her over to search herself. Meanwhile, I asked her if she had any backups.
Needless to say the abuse tripled. I never found the drive.
Which is actually not safe for cold storage in any way, shape, or form. Cheap flash storage devices are optimized for minimum cost per bit stored, not long-term data retention.
Why didn't IT use their powers to deploy a backup program before they deployed a deletion program?
Thought expermiment: what wuodt happen if a student accidently deleted school's files, instead of the reverse? Criminal penalties? Civil penalties?
Were these personal laptops, or university provided? The fact they have H: and M: drives mounted suggests the latter.
More generally: make sure you DR plan, even the simple "I have a backup" one that most people use, involves a second provider (which in some circumstances is your own local resources).
Even if the people keeping your data safe on a daily basis are entirely competent, bad things can happen and with centralised control they can happen to many people at once. Even if all the data can be restored you may not be a priority so if you need urgent access to the data having on off-provider copy you can take it from is a godsend.
Of course in a commercial setting or some university/research settings, maintaining an off-provider copy of any data may be a _massive_ policy breach. Or even a legal problem is it involves personal or other sensitive data.
The trick is to look at the most productive research groups, in terms of funding and output, and see if they use the resources from the IT department or not.