But, I feel like the comparison to Heroku isn't great.
Heroku saves you from having to do and worry about significant amounts of (I would argue) extremely important admin and security work.
How are datastore backups handled in this scenario? How do you handle updating redundancy? Can you in a couple clicks add a secure Postgres, MongoDB, Memcached or Redis server to your app? Setup CI?
Or even just secure these things properly. This stuff gets complex and it's extremely easy to accidently set up something that's much more open to the world than you would want.
To sum up:
Heroku -> A way for developers to put up much more robust sites than they could otherwise.
Scripted Setups -> a (very positive and cool thing) for those with devops/sysadmin skills to more rapidly setup a site.
Full disclosure: I do a lot of work in the Heroku ecosystem and could well be defending the platform out of greed. But, I've also seen first hand some of the wild misconceptions and mistakes that were caught by the built in systems and limits to the platform.