1 out of a thousand people might do that, the others will buy the product. That's why people use it, most people don't want to build everything themselves.
But as usual it forgets the "For a Linux user" part.
If we remove the whole linux section and just ask "why not map a folder in Explorer" it's a reasonable question, probably even more reasonable in 2026 than in 2007. The network got faster and more reliable, and the dropbox access got slower.