Take a very real example: Discord is working on video chat right now. As part of that work, it's not unthinkable they'd need to severely rework the voice/text protocols because they want to bring all of them in line with one another, reduce their tech debt or what have you.
If it's an open standard, they need to check in with everyone, document the move, potentially have to explain it or depending on popularity won't even be able to justify doing it. And suddenly, you see they're losing their competitive advantage for the sake of pleasing a few people on HN.
If it's a closed standard, they do whatever they want, don't have to justify or explain it to anybody. They can turn the protocol into fairy dust, run two versions of it for a while, and require a client upgrade if you want video chat.
Now, a few years down the line once Discord is established, has a solid business model and the protocol is clearly not changing anymore, then we can talk about making it open, allowing third party clients and we can really seriously start bugging them about it.
I very much want this to happen but Discord does need to be successful first. You'll get nowhere by bugging a startup to spend time on what could potentially kill the business.
