How come pokemon GTS wont allow direct communication?

whenever I fill out pokemail, trade on GTS, send E-Z mail on the GL or fill out my own trainer card, the game won't allow direct words or phrases. I can't choose the name of a pokemon that isnt on my pokedex. when I am on GTS negotiations all I am allowed to say is ( :D ), ( :d ), or ( <3), or ( ! ). is there some kind of problem where communication with strangers have become an issue? why have they gone to the extreme with banning human language and only allowing certain words or key phrases?