In light of the recent court ruling, I can see why many would not want it used as a security at all, opting rather for a password.
That court decision still requires a search warrant. . . and the simple way to even defeat that is to switch off the iPhone or iPad. Once you do that it requires a passcode, not just a fingerprint. Also, after not being open for 48 hours requires passcode. Then even a search warrant cannot compel you to open it. This court's decision won't stand scrutiny. His argument that it is similar to getting a fingerprint for ID purposes is specious, as is his equivalence to providing DNA for ID comparisons. These are two different purposes entirely.
Similarly a series of letters can be used to convey information or it can be a tool to unlock a door. One intrinsically is the data, the other only provides access to the data. Two different purposes. Similarly, a fingerprint, can BE the data or it can be the tool to access the data. Two different purposes. The judge has confabulated the purposes. Stupid.