Whenever the subject of the possibility of life on other planets comes up, usually right around the time that funding for various projects is due, we get a round of silly statements like "suggesting that life as we know it may only exist on this planet is arrogant" and things of that sort. It may be true or false, but it certainly isn't arrogant.
I basically agree with the late Stephen Hawking that we had better hope that there isn't life on other planets, or at least not life capable of coming here. It likely won't be friendly little ETs.