This looks more like a huge oversight than a malicious decision. I can't think of a good reason why a company advertising deliveries for a specific restaurant would redirect to a listing of similar restaurants. As an end user that would really annoy me; it's not like I'm going to change my mind and order Applebee's instead.

The only other explanation is that Applebee's is paying the delivery companies a fee to capture SEO acquired by them, which would be really scummy.