What political reasons? I googled for discord political controversies but didn't find anything too shocking.

I don't like depending on a proprietary commercial product to facilitate my personal relationships. I don't like the fact that they can (and are likely to) ban / block me from talking to my friends for choosing to run a client other than their proprietary web browser wrapper on my computer. I don't like that it's a single point of failure (that often does) for something as easy to host as chat. These reasons probably fall under the "not too shocking" label, but they're important to me.