If you accuse someone (not me) of having a small penis (I don't) they (not me) don't have to show that they (not me) have a large penis (like me). Just the accusation they made (to you, not me) is slander enough. But I'd gladly drop-trousers in a court.
I don't think it would be me accusing you of having a small penis (since of course you don't). It's me accusing someone named romcade4321 of being a generally shitty person, and also having a small penis. If you think romcade4321 is a reference to you, you would have to prove the similarity between them and you (maybe by dropping your trousers in court?)
I don’t think you’d get to use the courts anymore.
This is not the point. The point is about deterring lawsuits. The point is not about defending lawsuits. This is very clearly explained in OP.