"Could it be the whole "if I can't live freely, the way I want, it's better not to live at all" part?"

...!!! That must be it?? Oh OUCH. So he assumes that Shen Wei still feels this way (and he's not exactly wrong), and that HE made Shen Wei feel this way, ahhh?? (I have a lot of delayed realizations thanks to your comments. :D I feel like some of these things would benefit from being a bit more spelled out.)