No it is not patented, because the creators don't want only one group (them) to be solely benefiting from the success of iota. If they patented it, companies would have to pay money for the technology, and the founders would be making the money. They did not want that, they would rather work with the corporates to achieve goals. That kg also why the iota foundation is a non profit organisation.
In regards to someone coming up with better technology, it could happen, who knows.