Caddy for secondary Harddrive in MBP

My advise for using a caddy for MBP 2012 []i7 []16mb; primary drive 750gb; Secondary 1T(now) 128gb SSD(Before)

The result from after 6months of using a secondary hd for the macbook Pro, I arrived at the conclusion as unreliable for keeping anything you needed for safe keeping.

A. should not be used as a backup drive for data of necessary

B. Should be use as a trash can.

C. Death Cab for Caddy (since it is created a oneway system of dropping data without able to retrieve and backup/dead SSD 1/ Saved Data 0)