Staff shouldn't have to give out warnings for some things, but what makes you so sure they'd listen or understand the warning in the first place? People often copy and paste here because they can't speak or understand English very well if at all. People also even get temp bans  and come back and do the exact same thing they were banned for. Some people just never learn or take the warnings. Besides, I have actually written a welcome message that will hopefully be put into place soon* that will be shown upon sign up alerting users of the rules and warning what will get you permanently banned. If they don't listen to that warning then there will be no excuses.

*hopefully within the next decade