He's referencing that other ecommerce sites (e.g. walmart) couldn't just say "oh, one click buying is a good idea, and an obvious one, so we'll implement it too". By having Apple pay significant money for right to use the patent, it adds validation that it isn't a frivolous patent, and actually a useful, non-trivial, non-obvious solution which warrents being licenced.
It gave Amazon much better ground to file patent infringement against any competitor that attempted a 1 click checkout solution without licensing the patent, both improving chance of further licensing and reducing the chance competing ecommerce platforms would implement the feature without licensing it through Amazon.