> They are still doing it!

No, they're not! Debian uses PGP and signature verification to protect against MITM attacks because it is critically important for software downloads to be protected against MITM attacks.

Now, Debian does not use HTTPS in specific to protect against MITM attacks because they have another method baked into the package managers that people are using. It does not follow that HTTP is secure, it's not. It follows that you can use an insecure protocol to deliver software if you bolt the same security features on top of it.

You're looking at someone who has come up with an alternative way to protect users from MITM attacks and thus doesn't use HTTPS, and the conclusion you're drawing is, "I don't need to be concerned about MITM attacks." That's not the right lesson to draw from this.

Is your publicly facing site being accessed by software that automatically checks data integrity using a set of pre-shared keys? No, and no normal person is going to manually do that check when they visit your site, so you need HTTPS.

> If you are running a network where that's not possible,

If your website is accessible to normal browsers on the public Internet, than you're not on a network where that's not possible.

> LetsEncrypt is pretty much an advanced tool, for advanced users

Most free hosts I've looked at recently from Github pages to Netlify have automatic background SSL management for free with zero configuration from the user. If you're running your own server, then you're an advanced user, but even in that situation LetsEncrypt is one of the easiest SSL setups I've ever used.

Any situation where you're using a host who can't manage SSL for you is also probably a situation where you're using a host who can't manage things like DNS or hosting for you, at which point, yeah, I expect you to be able to run a command line tool. If you can install Wordpress on a server, you can use LetsEncrypt. If you can't install Wordpress on a server, you should be using a managed host, and they should install LetsEncrypt.

> It's breaking confidentiality. Which is one of the features of HTTPS

No, HTTPS encrypts data according to the certificate authority. While I don't like networks effectively doing MITM attacks on their own users, it is not the fault of HTTPS that it trusts the authorities that the user's device tells it to trust, any more than it's the fault of Debian if you import an untrustworthy key/repo into package manager.

I was kind of leaving privacy off the table here since you were championing Debian and Debian has substantial privacy issues with software downloads. But if you want to go down that route, than sure, another weakness of HTTP is that it allows tons of network snooping that really shouldn't be possible even for "innocuous" sites that claim they don't have private data on them.

> first of all, carrots and spinach are a panacea.

This is a complete sidenote, but either you don't understand what "panacea" means or you're at risk of Vitamin B12 deficiency. Carrots and spinach are not cure-alls for health, no.

> If the network is secure

It's not. Not if it's accessible from a browser on the public Internet.

> Wasting energy on useless cryptography "just because" is not very smart IMO.

Rejecting basically free cryptography that substantially improves security just because people are determined to be the last holdouts on a move that pretty much every security professional recommends is cutting off one's nose to spite one's face.

People being so concerned about centralization that they start sending messages in plain-text and start arguing with people online that sending messages in plain-text is somehow better for decentralization is at best misguided.