Oddly enough I'm someone who would find this useful. I have an echo dot in both of my kids rooms. I have the rooms set up so that I can turn the lights on/off with my voice, and play music for my youngest that she falls asleep to. Yesterday when I was rocking her to sleep my phone was in another room and I had no way to check the time other than to ask Alexa. Being able to see the time on the Echo Dot rather than ask Alexa would have been nice, but i'm also not going to go replace my devices either just to get that feature.
As far as security goes, my girls are young enough that the only thing they do in their rooms is sleep and read. Maybe when they get older and spend more time in their rooms I'd consider pulling them out. But for now I don't see an issue with it.