No, assholes need to learn to behave within the context of the instance / community they are posting to or get downvoted / moderated. Ideally they go away to their own instance where they can be assholes to each other and be defederated.
I'm glad to see that this perspective is popular on Lemmy. My biggest issue with almost every other Reddit alternative I've seen is that they're full of bigots.
What makes you think this platform has "free speech"? It has a bunch of tools for suppressing or excluding undesirable tools. Most obviously, moderation can be used to remove comments or users from an instance, and federation can be used to remove whole instances from the network.
I value free speech. But not every platform has to support it, and Lemmy explicitly doesn't - unless people just don't just those levers.
You can run your own instance or join an instance that tolerates that speech, and federate with other instances that tolerate it. So, the "platform" is not supressing you one bit. Go forth, and be an asshole if you wish.
However, administrators and users on other instances also have the freedom to participate without being forced to listen to assholes ad nauseum. "Free Speech" does not mean "Free (from the consequences of your) Speech" or that other people should be forced to listen to you.
The reason why Lemmy encourages free speech better than the major platforms is that people can just start their own Lemmy.
The argument that people gave for supporting suppression of political speech on platforms was that "you can just start your own site, you don't have to use twitter/fb/etc". With the death of reddit, we can clearly see that is much easier said than done, but I think Lemmy is making progress in that direction.
In the older, better days of the internet assholes would be banned frequently. The problem is that in recent years instead of having a large number of relatively small forums we have a few massive social media sites that effectively control communication over the Internet, and being banned from one of those would be a very big deal.
With the Fediverse, we can go back to the way things were, where banning someone from a given instance isn't a huge deal since people can just make accounts on other instances, but it's still enough of an inconvenience to act as a deterrent. And if they keep being an asshole on their new instance then they'll get banned again until the only instances that'll take them are ones that cater exclusively to assholes, and those can be defederated.