If physics, chemistry, or mathematics theories of similarly laughable imprecision were allowed to be put forth as "science" mankind would still be mired in the 14th Century.
The nice thing about being an evolutionist, archeologist, cosmologist or anthropologist is that you can say anything you want, because you can never really be proved wrong. It's not like developing a new medication where somebody is going to keel over and accuse you.
And, when the next Silly Opinion comes along and crowds yours out of currency, who is going to care? Old Opinions just fade away, and the holders never are held to account.