Kick. Problem solved. 95% of them won't come back.
There's absolutely no harm in making sure they don't come back though.
And uh, sometimes they do return.
If you don't want them to, then ban them. Don't leave it up to them.
What's the point in making such a big deal about whether you ban or kick people?
It's entirely up to personal preference.
And if you happen to have a popular server, as Tezuni does, then he's obviously going to encounter a higher rate of people who ruin the server than less-popular/less-hosted servers. I'm not even thinking about any bans he administers for his own personal reasons.
He's only suggesting a search feature for the ban-list.
It's not relevant if you never have enough people banned to warrant one.
You wouldn't be the one using it. It's not going to negatively impact your Blockland experience if it's implemented and you never use it.