Did you read all those lines yourself? Did you even confirm checksums matched before running them?
I think that's the parent's point. You can build from source, but how do you trust the source? Is it any more egregious to trust a prebuilt binary from a specific website than it is the raw source? If you can't trust the binary being hosted by the author/caretaker, can you really trust the source being hosted or maintained by the author/caretaker?