I mean, good for them? If they're "just rebranding and selling access for infinite markup" then surely the only people who would pay them are either too lazy or too busy to host it themselves, or too rich to care?
Would you prefer that people/companies that fall into these categories be forced to go through some _other_ reseller (who is just adding their own markup on top of the cloud hosting costs) instead of getting the service directly from their cloud provider of choice?
No, that's not the issue. They have a marketplace where ElasticSearch can be sold as SaaS. However, when there is something open source being offered on that marketplace, they co-opt it, give it AWS branding, and sell it themselves. They also own the infrastructure that both their own offering and the 3rd party SaaS offering is hosted on. Lets say they charge $1.00 / unit for EC2. They can charge $1.00 / unit for the 3rd party SaaS to run their service, and $1.00 / unit for their own offering which is basically EC2 + SaaS, so there is literally no way for the 3rd party to be price competitive, and meanwhile their own SaaS offering is blasted into the AWS interface everywhere, while the 3rd party offering has to be searched for and found. So they take the development work of that 3rd party and use their lock in and ability to steer customers to shut out the 3rd party, while taking all their work and selling it themselves at a price that the 3rd party can't possibly match (and not because of efficiency, because they'll just refuse to make a deal with the 3rd party to give an EC2 discount that they give all their other large customers if it would mean the 3rd party can then be price competitive with a SaaS offering that would compete with one of their own).
Would you prefer that people/companies that fall into these categories be forced to go through some _other_ reseller (who is just adding their own markup on top of the cloud hosting costs) instead of getting the service directly from their cloud provider of choice?