It appeals to gaming communities rather than business ones through it's design and features. You don't have to sign up to instances separately - there's a single account you use to sign into any, and you can adjust your picture/nickname per instance. It's got great streaming and voice channel features. Because of all this, it's the #1 platform for gaming communities, and many other tech communities opt for it as well.

There are some really vibrant programming language communities on Discord. The Python Discord always has very active servers, for instance: https://discord.com/channels/267624335836053506/267631170882...