What's the alternative tho? In the case his website goes viral, is Ghost supposed to just shut down the website when it reaches its limits? Sending a notice that you'll be upgraded in 7 days if your usage continues seems like a fair deal. (Perhaps it could be 30 days, but then Ghost is also just giving away their product for free)
He asked what would happen if he went viral, and his site was deleted without that question being answered. They appear to have a policy for that situation that would've likely appeased the customer so it should've been trivial to respond with that.
It would be standard practice to disable the "add staff" button after two users and alert the user to upgrade options. I can't think of a service that doesn't operate like this, actually.
He did, while including that they're trying to screw over clients, and implying they're a shady business in his email. Again, he could've asked this without making these accusations.
I agree, they should've disabled the "add staff" button.
He expressed his disapproval of one particular practice and I don't blame him. I think it's a shady feature too - getting people accustomed to a feature above their plan and then default-upgrading unless they take a particular step.
They have a solid policy for traffic spikes which is to be commended, but with something like adding staff, which is an active user decision, I think the method is reminiscent of dark patterns which this community tends to resent.