If it's between this and a perpetual logo, I'll take this any day.
I actually really like this approach. The action button isn't relevant in this context, and it doesn't occlude the content.
There's certainly situations where you wouldn't want this (ie if you're developing the app and you want to redesign starting from a screenshot), but for the average user I think this isn't overly hostile. I understand that people are dogmatically opposed to intent being modified, but I think you need to balance nuance. I actually enjoy having an attributable source in shared elements, and I think this is a low-impact way of achieving that.
It is strange how this spawned a 100+ comments discussion on HN.
I actually hate that apps are allowed to blank out content on screenshots, and this can't be disabled. There are apps completely mis-using it, e.g. mobile payment apps which hardly show any sensitive data in most cases, but now I can't share e.g. infos on screen with someone else easily.
It's a classic case of someone discovering a feature and thinking "hell yeah, so much security" without understanding or caring about UX impications.
I've yet to see someone saying "oh, I'm so glad my screenshot was blacked-out because I didn't realize I was in a banking app". It feels patronizing.