Hello Jesse,
Yes, we have another layer of security so that we don't allow installation of untrusted extensions (add-ons and plug-ins), while we freely allow installation of safe, trusted extensions.
So the decision is up to the user if he/she wants to install untrusted extension and possibly compromise his/her computer.
To install an untrusted extension, when you click the `Add to Chrome` button in the Chrome Web Store, you need to allow it in the Extension Guard popup, as shown in the screenshot:
If for some reason the popup does not appear, you can turn off this protection feature completely in the SPC by going to the SPC page:
and by turning off the Extensions Guard feature on the page:
I hope this helps to solve your problem,
Josef