I remember when this happened. It isn't as simple as "Linux libraries unsafe" though. IIRC the person who inserted the backdoor in XZ worked for a long time to gain trust with the maintainer and did do actual work on the utility before breaking bad. What is frustrating about this, and obviously big kudos to the MS dev who found it, is that XZ is used all over the place, including major corporations like Microsoft,
yet just one dude was the primary maintainer. They weren't receiving either financial or developmental assistance from any of the companies who relied on the software, I don't know if this has since changed.
Unsurprisingly, if you open a port to the internet you open a port to the internet. /s
This isn't true either. First, if nothing on your machine is listening on either of those ports external traffic has nowhere to go. Second, even if you have SSH listening on port 22 bots would still need to either exploit it, not impossible but unlikely, or know your root username & password. Relatively basic security hygiene resolves this.