Fair enough, as long as your happy to keep priming the content pump. There will be some posters who washout from such tactics.
Let's take the opposite extreme. Suppose I really dislike a community and I don't want it to grow. I could make a bunch of similar communities all over the fediverse. Every time someone posts to the target community I could copy it to a new community every 15m making it look like spam, and diluting any community interaction. Basically I could dry out the human interaction by dosing the content.
If we set the norm that top posting other people's content systematically isn't very Lemmy, then we would be in a good place to defend against such dilution.
Sure, some front ends like piefed may help, but not everyone is going to be using those front ends