No, it is neither dangerous nor bad for you. You have stumbled upon a little battle of the init wars. I will not get into this in detail but, briefly, the situation is as follows.
Linux has been using sysvinit for most of its lifetime. This is old and lacks features and the one thing pretty much everyone agrees on is that it needs to be changed. However, nobody can agree on what it should be changed to. Various alternatives were proposed, including--but not limited to-- the following:
Both of these are good in their own way and bad in others. As so often happens in the geek world, the choice of which init system (either one of those two or another) to adopt became something similar to a religious war.
So, you happened to come across someone who dislikes
systemd and, therefore, is proud of not using it. There are various people who have the opposite opinion and think that
systemd is wonderful and everything else awful. Just like there is on any other subject on the wide and wonderful interwebs.
Happily, the init wars are simmering down and are now past their prime. Most Linux distributions have decided to switch to
systemd. Even Canonical's Ubuntu, despite their being the force behind
upstart. So, today,
systemd is actually the init system of choice for pretty much all major disrtibutions except Gentoo (image source):