you only scripted it to do anything with $1, so that's all it's going to do.
you can use a while loop to perform the command for all nicks in the command (loop over $1-), or add a new alias:
alias kotunicka { kotunick $* }
that will perform the command on all the nicknames individually (or you could script that more elegantly to use one alias)
but I'm not here to write code for you, just throw out some ideas.
