I understand were you're coming from but I think you're missing the bigger picture in a way. For example, we actually do have admin rules, if you press F4 and click on admin rules you get this:
https://i.imgur.com/flHpBp4.jpgAlso it can be rather difficult to admin TTT. When you get a full server it can be hard to keep track of who RDM'd how many times, the less experienced people can forget who they slayed, and how many times. Also TTT can be hectic and that doesn't help. If it comes to a kick it becomes easier to remember that specific person because a kick would be a more serious action and thus a person is more likely to remember that.
We also have to account for the fact that there are about 6-7 people that actually donated for admin, they get rewards and limited admin access with the ability to ban for up to 2 days. Off the top of my head I know Kickguy, Dracs, Boss Murderer, Wassermelon all have donator admin, there are a few more. I think when you made this topic you were probably in general referring to the donator admins. There is probably less than a dozen of actual TH members that play TTT on a regular basis.
I myself have probably banned at least 50 people since the server has been up. MtDew even suggested being far more lenient for RDM's as it seemed to be the general idea on most other TTT servers and leniency seems a good idea with an immature young crowd of players. Perhaps re-iterating it to every admin would be a good idea, but it's not a good idea to try and force things down peoples throats, especially people on the internet as we are all used to complete freedom.
-Creams