I agree with the sentiment that the article reads as if "This is Yahoo's fault" - not to say they didn't play a role as the parent company. Bottom line here is that Tumblr (with or without Yahoo) failed to monetize their platform.
This line stuck out to me as very true reflection of what the Valley sometimes looks like:
> Tumblr’s stumbles under Yahoo may go down as a cautionary tale, both for the perils of a large corporation buying a hot startup and for Silicon Valley’s belief that any social network reaching hundreds of millions of people will inevitably generate boatloads of cash one day.
There was talk of "We'll make it an advertising platform" but did anyone really ask the Tumblr team "How" ? (I'd love to hear info from any insiders on HN)
Makes me wonder how many times a day the execs at Facebook wonder how they can ever monetize expensive companies like Whatsapp.