I do appreciate what you mean about actionability and tbh it's hard for me to comment on this new mixpanel feature set as there's not too much information on the sales pages.
However I've been investing a lot of time and code in Analytics and in mixpanel recently and while I would definitely agree that not all data is actionable, it doesn't stop it being useful or worth investing in as long as I take the time to examine (and prune) it afterwards.
What I find exciting is that these new types of Analytics open up value in for product design in a way that just wasn't practical without a tonne of custom dev before.
However, just as a new boss taking time to talk to each employee in the company isn't predictably actionable but still has vast value, so these new Analytics tools allow us to understand users in way that is not always actionable but is invariably valuable. The only real question surely is "is it valuable enough"?