I can see value in internet access. The lock having internet access means I can be on vacation in Thailand and grant a friend access to my house to drop off the rent check I left on the counter. And later, I can make sure my friend didn't forget. Or, make sure my dog-sitter is showing up. I also can't think of a more convenient way to grant access and identify people off-hand.
As for the connection going out, there are solutions. Redundant cellular connections, maybe? And if you really can't get in, it's not the end of the world. We already have solutions for that: locksmiths. Might be expensive though, and end up destroying the device, or maybe your door.
The data security thing is really bad. Unfortunately, that's a much larger problem though, not really related just to IoT.
I guess more broadly, I was thinking about a scenario in which the lock device dies, and making the point that conventional devices aren't foolproof either. In this case, the fool being me, and the proof being locking my keys in the house.
So, any lock can fail, but I'm not really concerned as long as it has a reasonably low failure rate. We've tolerated conventional lock systems failing (via user error mostly) for a long time.
As for the connection going out, there are solutions. Redundant cellular connections, maybe? And if you really can't get in, it's not the end of the world. We already have solutions for that: locksmiths. Might be expensive though, and end up destroying the device, or maybe your door.
The data security thing is really bad. Unfortunately, that's a much larger problem though, not really related just to IoT.