Dan existed in a time when there was no Afternic penalty for listing your domains at other places. Therefore, people would point their names to Dan and list on Afternic and get the best of both worlds.
Since the acquisition of Dan by Afternic, the option to point your domains to other services comes with a cost. If you do use non-Afternic nameservers, you pay an additional 10% commission fee to Afternic, or choose to not list with them and lose out on their partner network which has more eyeballs than any other service available.
Spaceship/Namecheap has their own partner network, but it's nowhere near the size of GoDaddy's. So, if you do use their landers, you're going to be penalized somehow. We can only hope in the future that their partner network grows to make it comparable to GoDaddy/Afternic.