The big problem is going to be when someone decides to start spamming and vote manipulating with bot populated private instances that automatically re-spawn themselves under a new name whenever they are blacklisted. Eventually, the standard will have to move to whitelisting over blacklisting, and once that happens the whole premise of federation starts to fall apart.
First off, Reddit (and Lemmy) is not a good place to learn about logical arguments and debate. The whole voting system is designed to filter popular opinions to the top and bury things that people dont like. If you sound authoritative and match your argument to the tone and biases of the community, your statements go to the top. If you get defensive or your answer doesn't match the subreddit you get dog piled with down votes. If there are any topics you are genuinely an expert in just go hang out in the appropriate subreddit and watch all the complete bullshit, half truths and personal opinions that get recycled over and over as gospel truth.