They spam the crying emoji because Synth refuses to stop them. When I was in the chat, I noticed some of them are just hardcore anime fans. I think many people join the spam because they find it funny.
I think Synth avoids banning them because he doesn’t have strong opinion over the morality of loli art, staying silent for the most part. This has allowed the behavior to grow, and he occasionally rewards them with neutral jokes to remain entertaining. Honestly, it wasn’t a significant issue within the Synthcel community before. Sure, many in the chat dislike lolicons, but they didn’t complain much because most people focus on Synth’s content and ignore the chat.
I’ll point out that, on one hand, Synth claims to have a free-speech chat (within the platform’s terms of service, of course), allowing lolicon fans to spam crying emojis and make common jokes from /v/ and lolicon communities. On the other hand, he silences certain phrases to make Kirsche more comfortable. This suggests he only bans things he personally dislikes while permitting behavior that could harm his brand. All he would need to say to avoid this aspect of drama is, “Please take lolicon discussions elsewhere,” but he remains silent, quietly tolerating it. I’ll present these facts and let the audience decide whether they think it’s right or wrong.