The best part of the fediverse is that anyone can run their own server. The downside of this is that anyone can easily create hordes of fake accounts, as I will now demonstrate.
Fighting fake accounts is hard and most implementations do not currently have an effective way of filtering out fake accounts. I’m sure that the developers will step in if this becomes a bigger problem. Until then, remember that votes are just a number.
There are legitimate reasons for creating a “low-usage” server to host your personal account, so you have full control over federating etc.
If we start assuming all small instances are spam by default, we’ll end up like email now—where it’s practically impossible for small sites to run their own mail servers without getting a corporate stamp of approval from Google.