The use case was server side data analysis. If it’s important work the researcher should get the much much more powerful server and run Linux like most sane people do. Who cares if your server can pair with your Apple Watch or use WhatsApp.
In any case, I suspect if you do a little discovery with that person - what specific problem are you trying to solve by staying with a Mac? - you'll find the answer. You might even be able to convince them to change their order if you find it's something that can be easily worked around in a way they hadn't thought of.
As someone who has been on the researcher's side of this conversation, I can tell you that I'm always happy to discuss my reasoning with someone in your position who's genuinely trying to help me. On the flip side, I get very annoyed when they're just being obstinate because they disagree with my choice on spec (and this is an endemic problem in corporate purchasing orgs.)
As the IT guy I also have to deal with when these macs break or they are misconfigured, which happens a lot more easily than the Windows machines because the latter are in a domain and managed. The Mac guys are way too “I know what I’m doing” until they can’t get the printer working.
If Mac didn’t involve huge increases in price and integration pains for the organization I would be less negative but that’s how it is.