This might be speaking the obvious, but I think that the lack of half-decent cost controls is not
intentionally malicious. There is no mustache-twirling villain who has a great idea on how to !@#$ people out of their money. I think it's the play between incompetence and having absolutely no incentive to do anything about it (which is still a form of malice).
I've used AWS for about 10 years and am by no means an expert, but I've seen all kinds of ugly cracks and discontinuities in design and operation among the services. AWS has felt like a handful of very good ideas, designed, built, and maintained by completely separate teams, littered by a whole ton of "I need my promotion to VP" bad ideas that build on top of the good ones in increasingly hacky ways.
And in any sufficiently large tech orgnization, there won't be anyone at a level of power who can rattle cages about a problem like this, who will want to be the one to do actually it. No "VP of Such and Such" will spend their political capital stressing how critical it is that they fix the thing that will make a whole bunch of KPIs go in the wrong direction. They're probably spending it on shipping another hacked-together service with Web2.0-- er. IOT-- er. Blockchai-- er. Crypto-- er. AI before promotion season.