"Run your code on our boxes" is a very, very small subset of cloud services. Does anyone other than Facebook care what instruction set they're using to ingest images? Does anyone other than Amazon care what instruction set they're using to serve S3 requests? Does anyone other than Google care what architecture they're using to crawl the web or serve ads or do something creepy with neural nets?
I don't get it. Having your software being able to run on two different plaforms, means that that software need to be tested twice, maintained twice. Your architecture decision might be optimal for one platform but not for the other, so you have to change your development process, have test env for both platforms, etc. You can't just cross-compile and hope it works.
All of this costs money, in terms of either having more developers/testers or having longer development time. So, in order to justify this investment, the second platform must be way cheaper in order to cover costs for extra developers/development time. And if there is a such huge difference and second platform works great, then why still have support for first platform anyway. Ditch it, and you will save yourself some money.
You could be an ISV, but again, your software will be more expensive if you need to support two different platforms. Which means that your customers must be willing to pay for it. Which brings us to same conclusion, unless there is a big saving by running software on alternative platform, nobody will care.
Google's data centers collectively use more electricity than the state of Rhode Island, or about the same as the entire country of Costa Rica. Their electricity consumption has doubled in the last four years. At average wholesale prices, their annual electricity bill would be about a billion dollars. ARM isn't dramatically more efficient than x86 in most applications, but specialised ASICs can be orders of magnitude more efficient.
I don't know about the standard offerings on cloud platforms, but people who do some sort of scientific computing care a great deal about the architecture and performance. As a C++ programmer, I'm constantly profiling my code to find out bottlenecks and optimize the code. Sometimes I even care if the CPU supports say AVX or some specific instructions.
From my comment: "the future of computing clearly involves an increasing number of specialised architectures and instruction sets".
I'm not saying that nobody cares about the choice of architecture, I'm saying that major tech companies with vast quantities of servers are beginning to develop their own silicon with custom architectures and custom instruction sets, precisely because that's vastly more efficient than using a general-purpose architecture that happens to be popular in the wider software ecosystem. The fact that nobody else uses that special-purpose architecture is unimportant, because it is economically viable for them to invest in tooling and training to write and port software for these weird chips.
