What if it was a lot cheaper and didn't require as many people to manage it? Certainly the markups on EC2 (and related) services are insane.
If I were a business owner, that is not a bet I'd make.
1. z-series experts are rare, expensive and typically old. Old does not mean unemployable, but it does mean a limited future career. Who's going to replace the current crop of experts? Internal education is a possibility that could work, but any way you cut the knot, it'll be more difficult than going with x86 and linux.
2. z-series hardware sucks. They are low volume parts who's main value is their backwards compatibility. If you think the hardware performance is acceptable today, will it be so in 10 years? Computer performance improvements have certainly slowed down, but peripheral vendors like nVidia continue to make solid progress. Even if IBM gets around to supporting them, you'll always be a 2nd class citizen compared to the PC platform: drivers, bus availability, etc. will be half baked or late.
3. z-series is off the main stream of computing. Huge numbers of talented software developers are building great open source software for linux (and other OS's) on x86. I don't know if administration on z-series can be done better or less expensively than on x86 today. I feel confident in saying that there will be no contest in 10-15 years. The pace of innovation is enormous, and IBM is not a company that can credibly make a commitment to bring that innovation to the mainframe.
4. Yes, mainframes can run linux and do various sorts of emulation. I don't think that that is a cost effective. I'm not alone in that assessment: if running mainframes was a cost effective way to run linux, I'd expect that to be the way big internet businesses run their internal data centers. They don't.
5. You'd have to deal with IBM sales. At least with x86, you have multiple sources for parts, and if you're big enough you can do contract manufacturing.
6. The markups for EC2 (especially the network transit) is really high. There is a continuum from Lambda and App Engine, through, EC2 to dedicated hardware rental like OVH and finally running your own. That is way more options than you have running on a mainframe: certainly way more vendors.
P.S. Huge fan of your writing.
I'm sure 100% of what you say is true, but there is no real reason for any of it to be true. Mainframes have many, many advantages over bullshit like the EC2. The sheer amount of containerized gorp, deployment scaffolding, management infrastructure and nonsense that goes along with it could be abstracted into something like zOS and into a Z-machine. Frankly it should be abstracted into something less ad hoc; EC2 ecosystem is total garbage from any sort of design point of view, and the fact that the world is now victim of their internal operations random walk is a tragedy. Originally it was supposed to be simple: now you need to hire a similar headcount to what you'd need for ops at a data center; arguably a much larger headcount than you'd need with a mainframe. To say nothing of the operational complexity of deploying scalable solutions on EC2 vs Mainframe.
I am not advocating people actually jump in the dying mainframe business; just that it arguably makes more sense than the EC2 from an engineering perspective. If IBM weren't run by risk-avoiding mental midgets, they'd find a way to beat Amazon at this, and the world might actually be better for it.
Cloud trivially can't be more expensive than on-prem. Cloud is just on-prem at scale where they sell you the leftovers.
By the way, there was a time when mainframes had multiple hardware sources for the same standard.
No amount of funny youtube videos or tag lines will paper over IBM's z-series pricing.
Probably not. The path of computing has been directed by economics: cost and its counterpart, volume. There's no reason why any greenfield project would choose to host on a mainframe.
The administrators are rare and expensive, the hardware is expensive and single source, and the performance is mediocre.
I can kind of understand why core business processes don't get ported off of mainframes: the business risk is too high. I just don't understand why anyone would choose to start a new project on one.