Are you sure that windows that, without your consent, are allowed to stay on top and grab your input are a good idea? And spawned by Chrome? As if we hadn't already enough ad-ware, click-harvesters, and spoofed dialogs popping up everywhere!
I know there is a couple of legitimate uses for this, but the ways it can be abused are vastly more.
I think the sensitive default should be to block it, and allowing it should be behind some user's conscious action. Yes, it adds some friction to some workflows and it takes a bit to get accustomed to. But it doesn't deserve the label "security paranoia".