First, people’s bans are considered confidential and their own personal business. That someone was banned is no one else’s business. That seems like a good thing and I would not want to see that changed.
Second, as the site is today, if you are banned, I can tell you in the ban reason exactly what you did that was rule breaking, including quoting what you said that got you banned. If the change you describe was made, I couldn’t quote what you said that got you banned if it was rule breaking, or personal. So if you said something racist, or something that exposed a personal problem that you have, then today I can tell you the thing that you said that was deemed rule breaking so you will know what you said that was rule breaking. That is very helpful when answering questions about “why did my post get me banned?”. That seems like a good thing to still be able to do, and I would not want to see that change.
Third, why would you want other people to see how often you were banned, and what you were banned for? Wouldn’t that be embarrassing and a violation of your own privacy?