(I have clients I recommend AWS to as well, but reducing ops time and/or reduced cost are rarely if ever part of those discussions; AWS is the luxury option)
Sometimes it's a matter of politics and trst - AWS is trusted, and if their hosting cost doesn't add up to much of their total costs, then that trust is sometimes more worthwhile than squeezing the cost down. E.g. I'm working on a project for a VC now, and their yearly hosting costs are likely to be below what I'm charging them for the initial development of their system, so spending time selling them on a cheaper provider is just not worth it for either them or me.
Yes, and too many companies don't realize that by moving to AWS, they are not only narrowing the pool of developers/operations people they can hire from, but the salary of these people is higher.
I'm not against AWS, there are absolutely businesses where AWS makes sense (as the article describes). However it's more than just a question of dollars and cents to move to AWS, you also have to factor in the HR consequences of losing access to dime a dozen developers/sysadmins.
For most businesses I have worked with, I would argue losing access to developer/sysadmin talent outweighs their perceived benefits of moving to serverless.
Thank you. Instead of being able to find a server ops guy from a large pool of experienced folks, you now have to find someone specifically with AWS-ops experience - a growing but much smaller pool of people, ime. Getting IAM permissions correct for complex stuff is just not simple, for example, and there's some use cases IAM stuff doesn't (or didn't) cover.
Had a client who couldn't give me EC2 access because - at least at the time - they'd have to give me access to all their EC2 instances, not just the ones I needed. Now... this may have been IAM-inexperience, although, at the time, my digging seemed to indicate it was the correct conclusion.