TLDR at bottom.

On most linux forums, it seems that everyone is trash talking flatpaks, snaps, docker, and other containerized packages with the statement that they are "pre-compiled". Is there a real-world affect that this has with performance and/or security, and does this have to do with canonical and/or redhat leaving a bad taste in people's mouths due to previous scandals?

Also, it is easier for the developer to maintain only one version of the package for every user. All of the dependencies come with the package meaning that there aren't distro-specific problems and everything "just works" out of the box.

I understand that this also makes the flatpaks larger, but there is deduplication that shrinks them as you install more by re-using libraries. Do the drawbacks of a slightly larger initial disk usage really outweigh all of its advantages?

I have heard that flatpaks are slower than distro-specific compiled binaries but haven't seen a case where this affects performance in the real world.

TLDR: In most forums linux users tend to take the side of distro-specific packages without an explanation as to why.