Well, you have to read past my first sentence. It's a list of things not a thesis statement. Together they make Discord notably bad compared to even other proprietary software. Especially since unlike MS Word where people pay money for the product Discord's product is the user.
But in particular the problem is that it's web crap and it pulls down it's code every time you run it. And now with the websocket backdoor it doesn't even have to do that. This is very different from a compiled program.
It's not surprising but it is also not acceptable. I chose not to use it and encourage others to avoid it.