Ghost.org does not like customer feedback
There are many things I learned working on B2C products, but one of the most important ones I learned early was that you will get feedback. A lot. And it will not always be in a civil manner. But even borderline insulting feedback is valuable - one of your features or part of your software pushed someone to forget that someone once taught them manners. So stay professional, listen to your customers, try to figure out what the actual problem is, appologise for their troubles and see if there is something to fix.
If you want to know what not to do look at the response from Ghosts CEO. I am linking to the wayback machine as the author removed the post. I still believe the whole interaction and especially the reactions are worth discussing.
It is no secret that I was and still am critical of Ghost. Considering the amount of money they spent to build a Node app connecting to a single database with a markdown editor that breaks OS level features I am simply not impressed by the product. But it looks gorgeous. It works. It fixes lots of the problems people have with WordPress after installing broken third party plugins. So I absolutely do not want to downplay what the team achieved, they executed well.
I also see why someone does not like to see their plan or subscription automatically upgraded. I am with Ahmed on that. I also see why a company wants to do this. Otherwise they either leave money on the table or lock accounts because customers do not read emails who would prefer to just pay whatever if their content accidentally goes viral. You cannot please everyone and this is one of the things you simply have to make a call on at some point.
I am no stranger to giving companies a hard time, even if more recently I decided to try to primarily focus on the things companies and products do well - except for you Ubiquiti. I would not use the words „fairly polite“ to describe the email he sent and also not the Tweet. But it was also not overly harsh. There was frustration involved, so communication like this happens, especially when you are a paying customer.
Rude or not: The worst possible reaction when you receive such feedback is to simply nuke the account. This is just plainly customer hostile, stupid and tells a story which company you do not want to do business with. If you like Ghost, host it yourself. Or find someone to host it. But I would think twice about trusting a company where the CEO throws a fit over customer feedback, calls them an asshole on social media and shuts down their paid account.