First off, there is nothing stopping anyone from making a bot that scrapes off raddle and posts it elsewhere. When you post publicly, its just that, public. In fact, there are likely already bots doing it.

Second, not using Lemmy because of the developers is certainly their choice, but its also like saying you refuse to use email because people you don’t like use it. Just be selective of the instance you join. And if you are that worried about something sneaky, the source code is even open source.