Because, if they looked at what you have written and your general standard of grammar, then they will have passed over our planet and classed it as void of intelligent life.
Tell me, do you mean exist instead of persist, or something else?
Might the fact that we live on the end of a spiral arm at the edge of or galaxy, a vast distance from any other likely inhabitable solar system that might even have the possibility of containing similar life forms to ourselves have something to do with this?
Even if you assumed that they are as intelligent as the human race then they wont go far, as we have only ever put a few men on the moon which is not far away at all in spacial distances.
Assume further that they were sufficiently developed to cover the inter-spacial gaps at a speed that would negate the effects of ageing and other physical difficulties, then they would probably see us as extremely primitive and warlike irresponsible aborigines and could probably investigate us without our realisation.
Then they would get extremely bored and go elsewhere.
Why bother contacting a civilisation that creates things like Big Brother on TV.. If it were me I would put up some warning signs in deep space advising all other intelligent beings to avoid the Earth as it it is not worth visiting.