YC has been actively seeking to grow as fast as it could since 2009-2010, and was funding over 70 companies in a batch as early as 2012, then they scaled back in 2013 after experiencing growing pains.
Plenty of well-known companies have come through in that time eg, Pebble, Stripe, Firebase, Parse, Crowdtilt, Coinbase, Instacart.
Cruise went through YC in 2014, after the time you (inaccurately) assert was the beginning of the "growth strategy".
BTW when Criuse first hit HN, commenters were generally nonplussed or critical [1], just as they had been with Justin.tv (some dude with a camera on his head??) and then Twitch (watching other people play video games??).
From the dude with a camera on his head to Twitch's $1Bn exit took 8 years, and even at year 7 people didn't think it was a winner [2].
I would love to start a multi-billion dollar startup like Zenefits and have the career that Parker Conrad has. He is LOLing all the way to the bank and his cushy consultant/VC job.