Our experience is based on successful hiring practices in North America. We don't have enough (read: any) data on hiring practices and resume review in Europe, Middle east, Africa or Asia. We really don't want to do any harm, so we are not yet able to offer our services there.
If you're based outside of US & Canada, but work remote for US or Canada office of a company, feel free to sign up. But if you're based outside of US/Canada and plan to work outside US/Canada, then we are not yet competent to handle your resume well.
I really like that you mention the geographic restriction clearly, and on the landing page.
I'm based in Japan, and often look at remote job boards. It's frustrating when you have to spend time digging into the content of job posting to find out you're ineligible - it's not much time per post, but it all adds up and it's annoying.
Welp! Is there any reason why you are restricted to US and Canada? I can understand 2+ years requirement.