From a technical point of view, neither is hard to do. I've done that for Akeeba Ticket System, for example.
However, I do not want to do that because it is a wrong metric to follow. The number of attacks blocked is NOT a good KPI (Key Performance Indicator) as you can do exactly nothing to affect whether someone will attack you or not. It's luck of the draw, plain and simple. I've often had clients complaining that last month only 1k requests were blocked whereas two months ago it was 50h requests blocked, does that mean Admin Tools is not working. No! It means that, not to put too fine a point on it, two months ago some lame script kiddie somehow ended up attacking your site, got his ass handed to him 49,000 times by Admin Tools and f... off forever.
The only reason you have a graph is to understand if a sudden spike in your page load time and your server CPU or RAM consumption is likely to have come from an attack. Really. That's all. You will only need to take a look at that graph maybe once or twice every few years.
Why would you need that information in your Joomla Control Panel?
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!