LLMs are a mirror. People that feed in behavior examples like these will get their text completion back mirroring their input. This is how LLM work. This doesn't mean the LLM are "toxic". This just shows the people obsessing over toxicity what they're obsessed with.
The point is that some use toxicity as a deliberate weapon, and that weapon can now be encoded into the LLM via training by those same aggressors. This multiplies their reach with minimal effort.
They aren't really teaching the model anything it hasnt seen before.
If you want toxic output, you can get it.