I think the liability is that now someone can log in remotely using [insert favorite control system here] app on their phone and turn on the fire. The fear is that maybe something happens and the house burns down because someone forgot they turned it on, or no one was there to realize there was a problem and the house was about to burn down. Anything can happen.

We do not control pool covers either...there is a reason they normally are a keyed switch. You just do not want to accidentally drown a baby raccoon or the neighbor's toddler because you thought it would awesome to be able to close the pool cover from your phone while you are in singapore.

I have no problem turning a fireplace on and off via a contact closure as roddy mentioned. Gas valve? No thanks.