This is no longer true for Instagram. It should generate $595 million in ad revenue this year, and is expected to reach $2.81 Billion in annual ad revenue in 2017. (Remember: this company was purchased for $1 Billion.)
So, to recap, Instagram was "massively unprofitable" for five years, after which it started bringing in revenue most easily measured billions.
In other words the notion that a product isn't "a product" until it's profitable is farcical.
Tell that to Instagram or Snapchat.