I wouldn't blame them for cutting off the free tier that allows one dyno to run for no cost. They should charge at least $10/month for what is now the free tier, and not time out apps (requiring loading requests). Make the small customers real paying customers.

The thing is: I don't understand why a large company would use Heroku because of the costs. Heroku seems like the sweet spot for a 3 or 4 person company where they don't have the economy of scale to manage their own servers.