I think that was intentional when you click on the CGC logo. You just have to click on the Trading Cards tab, and it will take you to CGCcards.com It's not on a dropdown menu. The tab is right there in plain sight. The CGC site shows all collectibles we grade, which include cards. I don't think it would be fair to the other collectibles we grade if you clicked on the CGC logo, and it only took you to the cards section.
It looks like the card selling, WTB and ebay/dealers forums are getting short changed with the link taking you just to the Trading Cards section. I might request this link at the top, where the Ask CGC link is.
https://boards.cgccomics.com/forum/101-trading-card-marketplace/