The end of an era. Simmons finally made himself enough of a pain in the ass to not be worth the money.
Bill Simmons was, in many ways, as good of a fit for ESPN as anybody not named Chris Berman. This is true. White, college-educated, upper middle class dude with thoroughly middlebrow tastes and an affinity for 80s TV and 90s NBA, like many of the rest of the white, college-educated upper middle class sports dudes. The 30 for 30 docs, often dubious artistically, were perfect in that regard. Safe nostalgia. Money makers. If nothing else, the Dr. V story proved Simmons is precisely that middlebrow guy, pointing out the "oddities" of the world. Nobody involved with that story stopped very long to think about the mental state/personhood of the subject.
Even though it found itself in the NBA commentary - which is itself is far too narrow a niche - Grantland has long been, in my mind, a costly vanity project, a way for Simmons to buy some cool, millennial talent he doesn't have in himself or the time to explore. The idea that ESPN had to throw more time and money into it...it's unwieldy as it is. It's restless and unfocused. It's a grocery store of twee.
Simmons' transformation from wise-ass to cool journo impresario at ESPN had to have a terminus somewhere. He was no longer content to be good at what he was good at doing, and ESPN, at long last, was tired of giving him more money to find such contentment.
It should go without saying someone will give him a billion dollars to run his own sports site.