They're telling you why: having a free tier means allocating a lot of resources to fraud and abuse, which are rampant in hosting, especially now that you can convert hosting dollars almost directly to cash. It's a big problem, and I have every reason to believe they're being forthright about why they've made this decision.
That may all be true but I don't see any other way to frame this other than them throwing in the towel for the whole platform and/or conceding to other platforms that are better at spotting fraud/abuse.
Require a credit card, require a deposit, allow free dynos for otherwise paying customers. Killing the whole program is a sign they don't care about growth, they don't care to be where a developer first launches a hobby that results in paying later, and they are fully embracing their Salesforce persona (not a good thing in my book).
I've never said there wasn't any. Just that if you value a free tier (which you should if you want to attract developers) you find a way to deal with the fraud (or eat the cost). The fact that Salesforce either couldn't figure out (or didn't care to) the fraud and didn't want to pay for it spells bad news for the future of Heroku.
Again I don't think you understand the amount of resources that goes into anti-fraud teams in the hosting world. I used to work at a big hosting company and we had a team of 50+ people working around the clock to stop fraud ontop of tens of thousands of hours in engineering time to automate as much as possible. It STILL wasn't enough. I can only imagine how much worse it is when you have a free product offering.
They could've converted the entire free tier offering to a $2-5/month thing, which would still be very attractive for legitimate users. Fraud is a big problem, but it didn't mandate this specific solution.
You can still offer a "free tier for existing customers" and call it "development" or something. This lets people who are already known/paying to spin up test instances, without having to go through purchasing, which leads eventually to more paid usage.
I guess it depends on where you think the platform is going, and which segment of the market you think the revenue is going to come from. I'm just saying: it's a significant cost. It's maybe the most important thing to know about the hosting business.
