When we were working on the HA Dashboard alphas and betas, I got into a similar discussion with @aimc regarding lock status on the lock widget and my initial position was the same as yours.
But as Andrew explained it, most users would want a notification tick when a door is open - an insecure condition - as opposed to a notification tick as an assurance that “all was well”. Also, since the door is going to be in a closed state more often than an open state, the status color would kind of end up losing it’s meaning.
In that context, it made an enormous amount of sense to me and I ended up changing my opinion completely.
Of course, being the kind of dev that he is, he went and made it an option to do it either way to allow freedom of choice… but I never went back to it as his explanation made perfect sense to me.