I don't really see the issue. I've subscribed to Technology maybe 4 times now? All that means is I get more tech in my feed. It doesn't really matter which specific community it is, does it? If there is an interesting tech-related story or news item I'm bound to get it on one of them, or all of them, and each post might have its own insightful comments on the subject. It's just more content and more opportunity for discussion. I think Lemmy will excel at bringing forward content in this way because you can sub to many different communities around a singular topic. You'll never be limited to just one place like a subreddit with mods who shape the content you get to see. If any one community started to be artificially controlled like this, there are 3 more who aren't.