Whether Babcock deserves to be ripped for this depends on what actually happened here (something we will likely never know).
Babcock being the coach of the team and the person who best understands who is going to play under what circumstances should have known before the season started that there was no room for Sandin on the PP or PK, and that he would be getting a max of 14 minutes a night (on a good night). That situation should have also been known by every fan who understands Babcock by the end of the first period of the season opener. That kind of deployment was and is terrible for development - something Babcock appears to also know.
So why did Sandin start the season on the Leafs? Why did the GM not send him down at the start, or after game 1 (or after realizing the mistake in not sending him down after game 1, after game 2 etc). Was this simply incompetence from the GM? And if the GM was being incompetent in not sending him down and Babcock knew this was bad for his development why did Babcock not force the GMs hand by scratching Sandin?
Or was this a situation - as we have seen from Babcock over and over and over and over and over and over and over and over and over again when it comes to young players - that Babcock repeatedly told the GM that he was going to give Sandin the kind of deployment that would be ok for his continued development, but once the puck was dropped each game Babcock reverted to his well known style of absolutely not trusting young players.