There's plenty of boring stacks on Unix that are free, in both senses of the word.
SQL Server licensing is another story. It is expensive, but I've also seen it handle heavy workloads on modest hardware without complaining. Though I don't doubt the same is true for Postgres and MySQL/MariaDB/Percona. From what I've seen, the constellation of reporting and BI tools around SQL Server are what make it appealing to enterprises regardless of cost.
First of all most software developers are not working in the consumer space. And for B2B you often get asked to have an on-premises option, either because the company doesn't trust you with their data, or because non-stop Internet connectivity can be a problem. And when deploying on-premises, the cost of the Windows licenses do matter a lot.
If the clients are just web browsers then you can save the company a lot of money, since the clients can be just terminals powered by whatever you can get your hands on. But if you assume Windows clients, well, the costs can be huge. And on the server side, remote maintenance is way cheaper with Linux boxes, because well, you can control anything on a remote Linux machine, securely, reliably and for free. Add to that the licensing cost of Windows, which isn't cheap because you can't run a server on Home edition.
Basically if your solution assumes Windows in any way on the customer's side, you're just adding unwanted cost that could have been your profit. And SQL Server is simply unjustifiable.
That's just anecdotal, though. Maybe we were just unlucky and worked with odd customers.
The vast majority of corporations have an IT department who's main skill is windows management. And for good reason.
There still lacks a decent Active Directory/Group Policy/ Exchange open source combo.
You are confusing "boring corporations" with "boring stack" (as in: stable, reliable, non-hipster)
I've had to use both Windows and Linux VMs on Azure, AWS, and elsewhere for applications like that and I haven't found the cost of Windows boxes to be prohibitive.
In other circumstances, such as the ones you mentioned, you're definitely correct. I was only trying to explain why one might choose Windows, not why everyone should. :)
Sort of. My understanding is with Datacenter, you license the virtual host (per-processor cost) and can run as many VMs on it as you want. So the incremental license cost of is zero, if you already license that way.
Other editions have some limits, so "it depends". But it's not just a "your solution uses Windows, so your customer must buy a license".
The other factor is support cost. If you're selling to an organization that can handle Linux, that is probably cheaper. If you're selling to an organization that only has Windows expertise, it's probably going to suck a lot of your support time to get them running on Linux -- and even though you may be able to do remote support more efficiently than you can with Windows, you're still going to be doing more of it.
Basically as a provider, you can never trust the customer's capability for maintaining the server that your solution runs on. It's much better to decrease your costs for delivering the required support.
Otherwise you're going to find yourself guiding somebody on what buttons to click in the Control Panel, for getting the damn network to work, on the phone, on a Saturday.
I'm not sure why you'd pay for licenses if the company is forcing you to have your product deployed on-premises. You would be an individual owner among the rest of the licenses which are owned by the company. That just sounds really dumb to do for both sides of the deal. Is this normal?
However, the author makes a good argument about boring stacks in general. Your boring Linux stack will be much easier to maintain than something on bleeding edge.
Because there's some other piece of software you want to use that requires it? (Lots of people seem to like MS SQL Server, for example.)