Mean variance optimization

Hello guys,
I got stuck in R13. In the Asset-only approach, the reading assumes that we start from capital market expectations (return and risk) as well as pairewise correlation of the investment set, to select an optimal portfolio with regard to the investor’s risk aversion…BUT at some point, the text says "Asset allocation decisions have traditionally been made considering only the investor’s investment portfolio " and i do not really see how the the investor’s investment portfolio has been considered.