That's not correct, the Web Component catalog is completely separate from Polymer. Polymer is a library to make it easier to implement web components. You can use Polymer without using any of the community's components.
What did he say that wasn't correct? He said he loves polymer because it gets him access to community made web components.. Made in Polymer...
He implied that https://webcomponents.org/ is part of Polymer, but it is not.
This creates great looking results pretty fast and also enables you to easily give back to the community by open-sourcing your own components. Last time I checked already 1100 components were listed, of which the vast majority seemed really well build.