That’s something I completely agree with. There’s one instance I’m a moderator on where I’ve had to block certain users by admin request due to personality conflicts so definitely wouldn’t want them being able to initiate a chat.
This is actually a bit complicated because it depends on the instance really.
On one instance where I’m a moderator, the official moderation agreement we signed says we cannot use any chat platform to communicate one on one with users about moderation issues. Everything is required to be done via PMs and the moderators group is required to be included. In this case being able to disable the chat but keep PMs enabled is actually important.
On instances where I’m just a regular user I’m perfectly fine with just blocking specific users if they’re particularly annoying.
Honestly, ideal world for me would be to have separate block lists, but the developer in me hates the idea of adding a bunch of extra code to support that when most likely if someone doesn’t want to receive user-to-user chats from someone they’re also not going to want PMs from them either.