malmo has a good point.
sometimes it is better when cheaters or other rulebreakers don't know if an admin is on the server. there are often people who are asking if an admin is on the server and if the answer is no (or they don't get an answer) they often start trolling or insulting other people, so we can punish them for that behaviour.
if a player really wants to know if a player is an admin he can check it on the hp.
but what about the players who are saying that they are admins but in fact they aren't?
well if we notice that, they get perm banned. one troll less on the server wich is nice and without rights he can't really do something. and to be honest. there are many players out there who are toxic as fuck and forcing the admins to take action. so its not that easy to be an fake admin on our servers.
but back to topic. if we want something like that, our owners have to implement it.
edit: i deleted your double/tripple post, malmo