Can you explain why monitoring user-specific behavior and reporting that to unknown, foreign locations outside of your jurisdiction (for most people) should be allowed in the first place?

That's not relevant. In scientific research involving people, participant recruiting and informed consent is the norm, and those studies lead to ground-breaking, life-saving research. Anything other than informed consent is unethical. Opt-out telemetry isn't ok when a large corporation does it, and it isn't ok when a free/libre/open source software project does it. That the Homebrew devs feel the need to spy on all their users in order to get statistically meaningful data means they probably don't know how to properly conduct a research study, too.