It is not whataboutism since SystemD is what you’ll use to run services if you don’t use Docker… If I say that mass transit is a terrible idea because it pollutes, and you point out that cars pollute even more, I can’t claim “whataboutism” to dismiss your argument.

Here’s the corresponding page for SystemD: https://www.cvedetails.com/product/38088/Freedesktop-Systemd.html?vendor_id=7971 as you can see there are even more vulnerabilities, which makes sense as the attack surface is even larger.