I would guess this test mainly applies when the network isn't established and/or and running on its own. If Company A offers a coin in exchange for a promise to build a network with the funds, it's easy to see how an expected profit can come solely from a promoter or third party manager's efforts. In the case of XRP, the network is up and running, so where does XRP's value derive from if there are no underlying business operations to produce profits? As you said, the value comes from demand of XRP, and demand is based upon XRP usage in the network. At this point, profits or appreciation from XRP comes from each individual purchaser, seller and holder of XRP, since they determine the usage rate by buying and selling. So, you, as a buyer, seller or holder affect the potential appreciation of XRP and are therefore not solely relying on a promoter or third party for profits.
Yes, XRP purchasers can profit from other participants in the network if they sell to each other. However, the network itself is not a common enterprise, because all XRP purchasers do not have common goals when they purchase XRP. One XRP purchaser may intend to hold XRP while another XRP purchaser may use XRP to facilitate a payment to another person in a different country. One purchaser may use XRP to purchase an item. One purchaser may use XRP strictly to purchase another cryptocurrency. Everyone in the network has different intentions on how they will use XRP when purchased and many purchases do not involve a profit motive at all. So, even if you argue XRP purchasers can profit from the effort of others (other network participants), the network they share is not a common enterprise, because each XRP purchaser's intended use of their XRP is different.