When a hacker chooses to attack something, that isn't random. They had to look at a lot of different pieces of software, and decide which would be the best to attack. The choice in this case was Systemd. In other words, if you are looking to do malicious things, Systemd is helpful.
Now I want you to imagine that every piece of software has a score, which tells you how useful it is to hackers. Systemd has a high score, and hence it was chosen for this attack. Your argument is that: there are other pieces of software with a high score so it's fine for Systemd to also have one, since without it there would be other things to attack. My argument is that we should reduce the amount of software that has a high score. Do you think my reasoning or your reasoning will lead to a more secure ecosystem?
Now I want you to imagine that every piece of software has a score, which tells you how useful it is to hackers. Systemd has a high score, and hence it was chosen for this attack. Your argument is that: there are other pieces of software with a high score so it's fine for Systemd to also have one, since without it there would be other things to attack. My argument is that we should reduce the amount of software that has a high score. Do you think my reasoning or your reasoning will lead to a more secure ecosystem?