I have Internet-connected smart locks on my house and I'm not concerned. I have Kwikset locks connected via Z-Wave to my Wink system. Granted, I have an independent alarm system that is not connected to Wink, so even if someone were able to hack my Wink and unlock the door, they'd still have a separate monitored alarm system to defeat. And two dogs. And they'll be on camera.
Besides, it's far simpler to kick the door in or break a window than hack the door lock. Though any action should the house be unoccupied or if we're asleep of course would trigger the alarm and summon the police.
Even if they cut the Internet to the house, the alarm has a cellular backup.
Having internet connected door locks has not diminished the safety of my home at all, but instead increases the convenience factor for me and my family. For example, a couple of taps on my Apple Watch from down the street will raise the garage door, unlock the entry, turn on the entry lights and kitchen lights, then trigger a door re-lock action 15 minutes later.