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.