Dropbox has an app ecosystem, Drive does not. The network effect is strong - if I'm a developer who wants to implement a trivial sync-across-devices feature, I'm going to use Dropbox because it's something my user probably already has.
Google Drive offers nothing that Dropbox doesn't, except more storage, which as you mentioned, is quickly becoming meaningless.
There are a boatload of apps that integrate with Google Drive. I am not sure how one can claim that there is no ecosystem; It looks pretty healthy to me.
I didn't say Dropbox would go away because obviously a player of their market size won't but to say Job's was wrong about them being a feature is also misleading.
So they have some clout with developers, SMB's and enterprise customers that's nice but a majority of their revenue comes from consumers who will find a hard time paying for Dropbox when Google will offer Drive for free.
Google Drive offers nothing that Dropbox doesn't, except more storage, which as you mentioned, is quickly becoming meaningless.