It's a bad chat client
I disagree. It's functional, free and everyone can set one up. Skype had bad quality and bad connections and for Teamspeak many needed to rent a server.
with lots of horrid attitudes and people
Yes and no. It's a tool and everyone can use it and like cars, screwdrivers or forks assholes use those too.
But yeah, many public servers are filled with these people, but even more are just about a topic/community/game and are fine. I joined one for team finding in a multiplayer game and everyone just does what the server is for.
It's basically a meme cesspool
see above. It's not a uniform platform.
and the fact that your discord has a "shitposting channel" tells me yours won't be great or even worth joining
True. That's where your actual point should begin. The way a server is ran usually dictates its audience. A channel like this of course attracts the very kind of people this anon and many others despise so much, me included.
By creating these servers, you are sucking the life out of boards like this.
That is my main concern, too. Usually you don't NEED a discord server for a board, because the board itself is where the community interacts with each other. I'd say even an IRC detracts from the main thing, but this one's dead anyway so I don't mind.
If you board isn't fast as 4chan and you can allow for multiple splitoffs of the commmunity it's fine, because new people will replace them soon and the site won't miss the traffic. But for slow boards it's not necessary and will almost always form a 2nd community.