Drew and Arash went to MIT, where their everyday computing environment was UNIX systems with home directories on AFS. For those who haven't used it, AFS is a networked filesystem sort of like NFS, except with a better authentication model and the ability to support failover on the server side.
AFS, NFS, Coda, 9P, WebDAV, SMB/CIFS, FTP, Windows roaming profiles, AFP, etc. were all around and (to varying levels) built into OSes well before Dropbox. Dropbox was a fundamentally different model: files stay on your local machine and get synchronized, instead of living on the network. The entire idea that live synchronization is the correct approach is almost entirely due to Dropbox's success; any OS designer before 2007 would have said "Yes, we have something as basic as a networked filesystem."
If you're objecting to the fact that it takes a commercial venture to explore and develop these sorts of ideas, I too dislike that we're in that place. But it's true. We haven't achieved a way to develop standard computer infrastructure without capitalism, yes; but we've certainly achieved meaningful technology that did not previously exist that's actually working for people.
(And, also, almost all of those protocols I mentioned were developed by profitable businesses like Sun or Transarc or Apple or whomever, and only made non-proprietary at great effort. The ones that started off with public specs, like WebDAV and FTP, were the worst.)