As of today, ownCloud will discontinue the web installer, which was only needed if you did not have SSH access to the machine where you were installing your ownCloud (for example, shared hosters with FTP only access).
Although shared hosters used to be helpful, as virtual servers are becoming more inexpensive and offer more possibilities for administrators, it is time to retire this means of installation.
Over time, ownCloud has become more and more complex and very powerful. Today, SSH access is necessary to run ownCloud - sometimes you may need to fix things on the command line.
Reworking the structure of ownCloud contributes to more stable and secure ownCloud setups. The setup script was outdated legacy code and we are committed to getting rid of technical debt slowly but surely.
Host ownCloud yourself to be sure that your data stays completely under your control.
Check out other easy ways to install ownCloud: https://owncloud.org/download/