These are some weak arguments against Terraform.
> loops and conditionals were impossible for a while
Yeah they were, in what version was it? 0.11 and 0.12 I think when those were added? But those have been there for a while. It was admittedly beta during the time and under active development. Regardless, its a moot point now, so not worth discussing.
Still, conditional statements are limited to ternary style operators as opposed to complex multi-line if-statements. That would be a stronger argument to make that I could agree with. However, this was a design decision made by the team not a technical limitation. The goal is not to make complex logic decisions inside the declarative nature of Terraform since it takes you away from the declarative (documentation-style) markup that it stands for.
Between using locals and modules and data sources you can still accomplish almost anything despite not having multi-line conditionals. The end result is cleaner, which is a design decision that was made.
> the minimum unit of reuse is a folder with a file in it
I don't really understand the problem with this. This is essentially how Go(lang) is too and other full blown languages. Its another design decision and not really a limitation. There are significant advantages to this, for example modules are folders and everything inside of them gets compressed into a single unit for replication purposes. Within that folder you can break your code up however you wish to improve readability and maintainability. This gives utmost flexibility to the author, and standardizes the consumption for the consumer. You can import a module and use it as a "packaged" unit without needing to understand how the author created it.
These just sound like opinions you have more than "ergonomic warts". If anything I could argue that both of these design decisions of the language actually make it more ergonomic to use (and consume) not less.
Its also worth noting that I mentioned multiple times authors/creators and consumers. Terraform is very much designed around being consumed and read, almost like documentation. If you talk to Hashicorp this is a huge motivation behind the DSL that is HCL. It was designed that someone who has minimal Terraform knowledge could use modules to create powerful infrastructure within a company. This is how we use it in our company. The SRE/Platform Engineers (where I work) build very advanced, complex, and powerful modules that are easy to consume with a handful of variables.
We have developers that can spend a few hours learning Terraform and know enough to build production infrastructure within the company that is built to our design standards and security compliance requirements. They often don't even have to know what that is, they just declare a network, a database, and a cluster of compute with a handful of parameters that are auto-documented and they end up with some incredible infrastructure as a result. This is what Hashicorp is designing Terraform around. If you meet with them or go to their conferences, this is the direction and purpose of Terraform and how they designed it. A handful of Terraform experts at a company can create modules that are consumed by developers that have minimal knowledge of Infrastructure or Terraform. Its a powerful system.