Backup "everything"? That will take a nice chunk of infrastructure - network, servers, storage, ... Though de-duplication can cut storage down quite a bit on copies of the same OS.
But will you have to install agents in my machines? How will you still get me the CPU power I paid for if your agent starts sucking at peak loads? You better not lock any of my files. Will my system ever stall during a snapshot? For virtual machines you could play games with the block storage they live in. But what about where I bought dedicated bare metal?
What about my databases? A file system level agent (or a block storage snapshot) cannot be assumed to get consistent images, of that application specific file structure, that can be restored to a usable database. Will you have agents for every database engine? How will that agent "pause" the database between transactions to get a consistent image? For engines that do not have an appropriate API, how will you do a dump-to-disk for a file system level copy? Would that take away from the storage space I have paid for to hold my applications?
How will you test restores? A backup is not a valid backup until it has been tested.
AAAARRRGGGG t h e h o r r o r
I have not been in a Backup Team for awhile, but still get damn flashbacks.