Because when I join a game on DW the expectation is that the game will be played in DW. That the plotting will be done in DW. That the RPing itself will be done in DW. I hate Discord, it's an archival mess: its search function sucks, you can't pull up logs by unique URL, username, etc. So if a game advertised itself as DW but a significant portion of it was done in Discord? I'd feel lied to.