If the competitor offers https://www.dropbox.com/install-linux, developed in the open with a GPL license, is it reasonable to tell other people to take on the cost of building and maintaining a client for your paid service?
Which aspect of chromiumos drive integration and sync engine is not "developed in the open"? The dropbox source is distributed as a tarball and if you want to contribute to it "contact us". That doesn't meet my definition of "in the open".
I didn't claim that ChromiumOS's code wasn't developed in the open. The fact remains that Google neither supports nor provides a Google Drive client for Debian and its derivatives or Redhat and its derivatives, while its competitor does. It is reasonable for people to complain about this.