Though in that case it's very much because their software platform utterly sucks - given how the Lockitron works I'm amazed they have anything at all.
No local LAN support - everything tries to go over the internet, and their servers are unreliable. Lag time of something like 30 minutes is not uncommon.
Doesn't integrate with a lot of existing doorbell/intercom systems (ostensibly it'll work with AC ones, it didn't work with mine which is admittedly some type of DC - but simple enough, short to ring and all that).
It is all round a terrible product which was launched in an unusable state, with really poor design decisions.
How's the battery life on door bot?
No real idea about battery life - its been sitting on a bench somewhere for the past year or so, since we gave up when we realized it was going to be either the Doorbot or the doorbell which actually rang, and found the notifications on phones were unreliable. We also realized that at home, you usually don't have your phone on you or even necessarily nearby - hence the doorbell.
The one nice thing about the Doorbot was they were trying to solve the battery issue by letting you draw power of the doorbell circuit - but since ours isn't AC (or has to low of a "ring" current) we couldn't use that.
There also appears to be no progress being made to resolve these issues. Just look at the reviews for the android app.