Should you back up data stored in AWS S3?

AWS S3 is meant to be very reliable using normal multizone storage tiers.  You can also easily replicate to a second AWS region giving you 6 copies of your data, on two continents, with good security and minimal fuss.

Asking around, it seams I am in the minority in thinking we should suck a copy of our data out of S3 and keep it elsewhere.

I have heard several reasons to NOT backup data from S3:

1) Cost of egres

2) security.  If you have a copy of the data, you need to secure it.

3) If AWS has a total failure, or even just one AWS region (eg Sydney), we will have much bigger problems than not having access to our own data.  Many important government and industry functions will stop.

Thoughts?