Since the OP is specifically talking about Discord, it’s worth mentioning that what you’re talking about doesn’t seem to be the case for them - they make money from Nitro subscriptions and their game store, and state in their privacy policy that they are “not in the business of selling your information” (https://discordapp.com/privacy, in the section ‘Our Disclosure of Your Information’).

So relating back to the post, their justification doesn’t necessarily make it right, but I think it’s incorrect to attribute it to a malicious cause.